If it was a matter of shooting for a movie then he could have shot for both simultaneously,especially since most of the movie is being shot in Mumbai.Even in the BBC network interview he failed to confirm his exact time frame of return...it was along the lines of "something like 4 weeks"...I mean how vague is that coming from the lead actor of a popular soap??!!!
I won't believe any rumours/spoilers concerning his return until I actually see him onscreen again.
Being a loyal fan of IPKKND,I'll try my best to enjoy the show in Barun's absence,all the while hoping that the CVs manage to keep the track entertaining...but I fervently pray that if Barun doesn't return and the PH replaces him then the show doesn't suffer the fate of Laagi Tujhse Lagan on Colors.