I think you may be on to something there — a former airplane mechanic reported hearing sputtering (compressor stalls) just before the impact. Could have been due to damage from the trees, unless they were already experiencing compressor stalls that caused them to lose altitude. 1/4 mile at probably 130 knots (over 2 miles/min) is not long, probably 60 sec divided by 8, or about 7 seconds before impact.
Thanks for your service, those guys in the tower had a really tough job this morning.