Is this a bluff or credit with holding

[stokken]

Mp 180 sng blinds 25/50

Mp AQ [img]/images/graemlins/club.gif[/img] 4K stack raises 3xbb, button calls 5K stack( has shown down TT on rag board and doubled trough a player who bet his A-7 all the way, and won a big pot with a flopped set.Has only played these two hands unless in blind sofar.
BB calls to

Flopp Q [img]/images/graemlins/heart.gif[/img]8 [img]/images/graemlins/heart.gif[/img],4 [img]/images/graemlins/club.gif[/img]

OOP bets 120, button raises to 400, bb folds, oop calls

Turn T [img]/images/graemlins/heart.gif[/img] Oop checks, button moves all in