Hebog,
The thrust variations resulting from the RPM changes during the upward half of the accident manoeuvre would probably not be noticeable. The Hunter T7 has quite a quiet cockpit and you would be decelerating. The change in noise would probably not be noticeable and no significant extra deceleration would be felt. If a major (total) loss of thrust occurred, you probably would notice the reduction in noise and probably the best (but not necessarily obvious cue) would be the increased aft stick force and displacement required to maintain flying on the buffet (as was the case here) as the airspeed reduced more than normal.
DA minima are AGL heights. AGL will be used in a report such as this because that is what is important for safety. However, AMSL is also important because that affects the performance of the aircraft and the IAS/TAS relationship. So saying, it is actually density altitude that is really important for aircraft performance.