depending on what interperetation it may also pertain to an engine start. The ITT will rise as fuel is introduced and the N2/N1 spool up- after starter cutout and N2 stabilization the ITT drops back from the peak (of the start) by about 100 degrees C. I cannot attest to a 777 as I don't fly one, but a CRJ-200 will start and the ITT will rise to about 615 deg C, after N2 passes 55% and the starter cuts out, the ITT will roll back to about 515 deg C as the N2 stabilizes around 62-65%. These are round about numbers and different temp/alt conditions will change the numbers but the overall ITT rise/drop remains the same. Also on the CRJ with a reduced thrust aka "flex" takeoff the TO power will typically be 85-86.5%N1 instead of around 90% (normal TO carats), Climb carots are typically in the 90% range and increase as you climb (obviously these are ballpark numbers as well since temp/alt effect the perf numbers). So depending on the question rollback could have a few different meanings. Since ASA has the -200 it may simply pertain the the ITT "rollback" during starts. Hope that helps more than it confuses, although the facts on the 777 are cool- learn something new every day! As far as in relation to the original link- sounds like the rollback was a computer generated power rollback (reduction). But I am just a newbie...