I know that vaulting over cover is planned for the game, but I have been playing a wee bit of Gears of war 3, and one of the things you can do in that is vault over the cover, and if there is someone on the other side you knock them back, Then shoot them, hopefully...
This could apply to Xenonauts as a valid tactic, as it would not the enemy out of cover, and force them to stand up. Granted it would be done cautiously as your man would be on the wrong side of the cover, but if you're having a hard time killing an entrenched enemy...
Animation wise, well I don't know, perhaps you could just try running the 'get into cover' animation backwards? Maybe with a bit more staggering perhaps?