If you use the pocket tank in an attack and choose to deal the attack damage first, what happens if you kill your target? Can you still place the particle tank? Also what if what you killed was a piloted vehicle would the pilot be placed on the map before the tank?

...THAT CAN RETURN TO ITS ORIGINAL SIZE: When an adjacent friendly character attacks an opposing character, the attacker may modify its attack value by -1. If they do and hit, replace Pym Pocket Tank with WizKids MP17-006a Pym Particle Tank on its orange starting line with one of its squares adjacent to the target. If the attacking character is named Ant-Man, Giant-Man or Hank Pym, use the yellow starting line instead. When replacing this character, you may ignore characters and blocking terrain when placing it, then destroy any in squares it's placed into. Any characters in squares it would be placed into are placed adjacent to it and dealt 2 penetrating damage.


Wrecked vehicles:
Remove the vehicle from the map and place a standard heavy object in one of the squares it occupied. Place the pilot into or adjacent to the square of the placed object and roll a d6. On a result of 1-3, deal the pilot 2 unavoidable damage; 4-6, deal the pilot 1 unavoidable damage.

If the character is KO'd, then there's no target to place the tank adjacent to. You then don't get to place the tank.

The replacement happens on a hit, which is before damage is dealt. So the character will still be there when you place the tank and will be KO'd afterwards.

Unless you resolve the attacks damage first, as the Smurf pointed out.

Absent errata, either way can work. But for strategic reasons, one may be more preferable in the moment.