Whilst the radar altitude returns might appear to show that the aircraft was above the height of the peaks shortly before the accident, that might not have actually been the case. Presumably these altitudes came from IFF Mode C returns, which are based on 1013.2mb. If the actual pressure was significantly lower (either due to weather systems or local orographic effects) then it might well have been the case that the aircraft was below the peak altitude all along. So this data will need deeper analysis before being treated as conclusive.