Hi,    That can explain why you can have the exclamation mark on it. As the firmware is not recognizable, and may cause some conflict. You will not be able to flash Dell drive firmware if it's not Dell drive. Though, it doesn't mean you cannot use the drive, it just will tell you that, the system is detecting something "alien". 
I have a PowerEdge T620 that had 1 of it's 2 RAID disks start to experience errors so I replaced it with another Seagate ST3300657SS drive. The new drive came online, rebuilt, and is working but is showing the yellow exclamation which I suspect is due to the firmware being out of date. The new disk shows hardware revision 0006 where-as the old drive was using ES66. I installed the firmware update to ES66 again hoping that it would update the new disk but it did not. How can I correct this?
Updating HDD firmware with new drive