There is a timer once the attacking gang fails a Bottle Out Test. On the first turn when Bottling the Game ends on a 4+ of a D6. then 3+, then 2+, then 1+; making the game more likely to end.
Defiling looks to score more VPs.
The issue will be that the gang on the home-turf won't ever bottle out. There should be some generic rule about conceding the game early if necessary. This would prevent the punishment, So the attacking gang can escape, once they've scored some VPs, but I can't seem to find any rule like that now.
Yeah, the issue is that there's no way for the attacker to trigger endgame without bottling out, and they only bottle out when some guys are Out, likely netting VPs for the defender. Apparently there's a rule in similar Gang War scenarios called Taking Flight which lets attacker within 1" of board edge remove themselves from the board and count at Out, thus aiding the attacker by depriving the defender of VP opportunity and speeding the Bottle roll fail.