user21048: Our freestyle ski team is looking to invest in a system that allows athletes to immediately review their competition ski runs with their coach after they get to the bottom. While they're playing back the video of their run, the camera will need to be available to shoot the next athlete. In an ideal world, a tethered camera would record directly and automatically to a folder on a laptop so that the athlete would be able to replay their run independently of the camera, leaving the camera free to keep recording the next athlete.
I've experimented with a Canon 5Dmk4 and the EOS Utility, which seems to automatically detect when the camera finishes shooting a video, and then prompts you the option of saving that file to your computer. This involves a lot of manual interaction, can take 30+ seconds to transfer a minute of footage, and ties up the camera during that transfer, preventing you from shooting the next skier if the transfer isn't completed in time. It's also a bit tedious and requires a coordinated effort between the videographer and the coach doing the video review. 
We are hoping to invest in the GH5 due to it's slow motion capabilities, but am uncertain if this will pose new challenges (i.e. file sizes), or offer any solutions. 
I'm familiar with the Ninja recording monitors being able to save to an SSD, but I'm curious of a solution that would allow me to instantly view recorded footage on a laptop, while leaving the camera free to shoot more video. I'm open to anything that would allow us to achieve what we're after as cheaply as possible!

user22861: 
look for a camera that can trigger recording on/off by it's HDMI output (used when you have something like a atomos recorder), not sure which current models can/can't but any dslr that's marketed as a video camera should do it. 
run a hdmi cable to a hdmi capture box ( I think HDMI can do 15m without a repeater ) 
hook the capture box to a laptop 
use software that will start recording when the camera presses record. 
use software like stream to me 
coaches can use another device ( tablet/laptop etc ) to display the recorded run

Using this setup you can have the camera recording runs while multiple people can stream any previously recorded run at the same time. As long as the software can detect the record flag from the camera the whole process is automatic, playback can begin for a file the moment after recording has stopped. 
I'd recommend a black magic thunderbolt ultra studio mini
for the capture box, it comes with Media Express software which will auto trigger when it receives a record flag from the camera. The mini is bus powered & small so it's keeping your cables down & means everything is running of batteries if needed
Stream to me is an iOS app for the playback but the companion app Serve to me is Windows & Mac & that lives on the laptop watching the folder that Media Express records too. Alternatively I'm sure a bit of google will find an android substitute for this part of the link. 
All that reasonable cheap, meets the need of recording while simultaneously playback (actually a pretty hard thing to do without spending big bucks) & once it's setup should take care of itself, while you concentrate on practice. 

21048: <p>Our freestyle ski team is looking to invest in a system that allows athletes to immediately review their competition ski runs with their coach after they get to the bottom. While they're playing back the video of their run, the camera will need to be available to shoot the next athlete. In an ideal world, a tethered camera would record directly and automatically to a folder on a laptop so that the athlete would be able to replay their run independently of the camera, leaving the camera free to keep recording the next athlete.</p>

<p>I've experimented with a Canon 5Dmk4 and the EOS Utility, which seems to automatically detect when the camera finishes shooting a video, and then prompts you the option of saving that file to your computer. This involves a lot of manual interaction, can take 30+ seconds to transfer a minute of footage, and ties up the camera during that transfer, preventing you from shooting the next skier if the transfer isn't completed in time. It's also a bit tedious and requires a coordinated effort between the videographer and the coach doing the video review. </p>

<p>We are hoping to invest in the GH5 due to it's slow motion capabilities, but am uncertain if this will pose new challenges (i.e. file sizes), or offer any solutions. </p>

<p>I'm familiar with the Ninja recording monitors being able to save to an SSD, but I'm curious of a solution that would allow me to instantly view recorded footage on a laptop, while leaving the camera free to shoot more video. I'm open to anything that would allow us to achieve what we're after as cheaply as possible!</p>
 22861: <ol>
<li>look for a camera that can trigger recording on/off by it's HDMI output (used when you have something like a atomos recorder), not sure which current models can/can't but any dslr that's marketed as a video camera should do it. </li>
<li>run a hdmi cable to a hdmi capture box ( I think HDMI can do 15m without a repeater ) </li>
<li>hook the capture box to a laptop </li>
<li>use software that will start recording when the camera presses record. </li>
<li>use software like <a href="https://www.zqueue.com/streamtome/" rel="nofollow noreferrer">stream to me</a> </li>
<li>coaches can use another device ( tablet/laptop etc ) to display the recorded run</li>
</ol>

<p>Using this setup you can have the camera recording runs while multiple people can stream any previously recorded run at the same time. As long as the software can detect the record flag from the camera the whole process is automatic, playback can begin for a file the moment after recording has stopped. </p>

<p>I'd recommend a <a href="https://www.blackmagicdesign.com/products/ultrastudio" rel="nofollow noreferrer">black magic thunderbolt ultra studio mini</a>
for the capture box, it comes with Media Express software which will auto trigger when it receives a record flag from the camera. The mini is bus powered &amp; small so it's keeping your cables down &amp; means everything is running of batteries if needed</p>

<p>Stream to me is an iOS app for the playback but the companion app Serve to me is Windows &amp; Mac &amp; that lives on the laptop watching the folder that Media Express records too. Alternatively I'm sure a bit of google will find an android substitute for this part of the link. </p>

<p>All that reasonable cheap, meets the need of recording while simultaneously playback (actually a pretty hard thing to do without spending big bucks) &amp; once it's setup should take care of itself, while you concentrate on practice. </p>
