Can Pile in take you away from a vehicle?

[Tepogue]

Ok, heres the situation.

5 Deathwing terminators, declare multiple charge against a Space Wolf Squad and an allied Chimera. Deathwing win combat by killing more space wolves. Chimera is only glanced 1 time. Does the end of combat pile in, make me leave base contact with the Chimera? My opponent said yes, because I cannot be locked in combat with a vehicle.

[Tynskel]

no. because you are in base to base already with an opponent's model.

The terminator can bonk the chimera, but the chimera's defense is to move away.

[DarkLink]

You're locked in combat (there's no half-locked for non-vehicles, you either are in assault or you aren't), and you are in base contact with an enemy model. That's all you need.

[Archon Charybdis]

AFB right now, though I think Tynskel has it right. Depends on whether or not the book says anything to the effect of "If Locked with an enemy unit, you must make a pile-in move yadda yadda". If it just says you must pile-in to b2b with an enemy unit (not specifically a locked unit) then you're all set.

[Nabterayl]

AFB right now, though I think Tynskel has it right. Depends on whether or not the book says anything to the effect of "If Locked with an enemy unit, you must make a pile-in move yadda yadda". If it just says you must pile-in to b2b with an enemy unit (not specifically a locked unit) then you're all set.
The rule only says "At the start of each Initiative step, any model ... that isn't already in base contact with an enemy model, must make a Pile In move." It says nothing about having to be Locked with the enemy you are in base contact with. Ordinarily, the multiple charge rules ensure that any model you are in base contact with you are also Locked with, but since non-walker vehicles can't be locked, they're an exception. So Tynskel and DarkLink are right: the Deathwatch terminator(s) in base contact with the Chimera didn't have to Pile In; they were already "in base contact with an enemy model."

Of course, as Tynskel also correctly pointed out, because the Chimera wasn't Locked with the Deathwatch, presumably it would just drive away on its turn. Then, in the ensuing assault phase, any Deathwatch terminators who used to be in base contact with it but now were in base contact with nobody would be forced to Pile In against the Space Wolves as normal.