B777 Undifferentiated or Other Model
Communication Breakdown; Confusion; Human-Machine Interface
Deviation - Altitude Excursion From Assigned Altitude; Deviation - Altitude Overshoot; Deviation - Speed All Types; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter Unstabilized Approach
Flight Crew Executed Go Around / Missed Approach
Human Factors; Procedure
On approach ILS XXR; Captain was flying the approach.  While on autopilot; Captain was attempting to acquire the glide slope from above.  Captain had been briefed--twice--by the First Officer (FO) on using the VSI to descend between 1000-1500fpm.  Captain elected to configure and use speed brakes.  Captain called for Flaps 25/30 with speed brakes extended.  FO called for speed brakes to be retracted first.  Upon speed brake retraction; aircraft pitched up.  Aircraft then began a climbing left turn on the autopilot.  Captain became confused as to why the aircraft was climbing and turning and attempted to override the controls.  Relief Officer (FB) called 'Go Around'.  Captain was slow to initiate go around procedures.  Aircraft got 10+knots SLOW and SLOWING while trying to follow the Flight Director Command bars.  FO directed Captain to lower the nose as we were getting excessively slow (while in the climb).  Captain accelerated and called for Flaps up (from flap position 20/25) and FB called for gear up.  Aircraft climbed to 3400+ft (cleared altitude was 3000ft) and accelerated to 270+knots.Captain later admitted his finger had hit the TO/GA button causing the aircraft to go around on autopilot. I now am unsure if we oversped the flaps; because maintaining aircraft control was priority.  I do not know if the Captain put a writeup for possible flap overspeed into the maintenance log.  Second approach and landing were uneventful.
Asked about the altitude where these events occurred.  He said it was about 2500 feet.  He also said there was no problem with the aircraft and that the retraction of the speed brakes was the reason for the nose to pitch up.
We were proceeding toward ZZZ for the ILS to 8R. The sun wasn't out yet and I was caught high on the approach. I mentioned that I didn't think we would be able to get down enough to have a stable approach but we continued. (1st sign of bad judgement on my part). We were barely within the parameters of gear down and flaps 20 at 2000 ft. I was able to get us configured by 1500 ft.; but we were still high on the approach by at least a dot and a half (or so). Here it comes. So; in an effort to save the approach; I extended the speed brakes and that was my biggest mistake. Go around was initiated at 1500 ft. (or so) and because the plane was turning left and we need to go straight; I disconnected the auto pilot; adding to my workload. Things were happening fast and I exceed my climb clearance by about 320 ft. after that everything slowed back down to normal and a normal approach and landing was made. As a side note; FB was awesome. OK; this is the part of what I learned. 1) Don't try to save a bad approach. We were caught high and I should have acted more conservatively sooner. 2) No speed brakes past 5 degrees per SOP. 3) Brief go around procedures along with approach briefing. (i.e.; flaps gear and FD procedures to remove and auto pilot off temptations). Use vertical speed to catch glide slope per SOP. 4) Always keep in mind that it's been a long night regardless of how I think I feel. Pay particular attention to every step of every procedure and clearance and recognize my limited experience on this aircraft.
A B-777 aircrew were flying an unstabilized approach when the jumpseater commanded a go-around.  The Captain was confused and slow to respond and may have inadvertently hit the TO/GA button; causing the aircraft to climb through the 3000 foot level off altitude.