Suspicious fold

[speedgun]

I have played with this villain many times before this, but haven't had any chat with him or any other history except, of course, I won a few pots against him in this sat and before.

A satellite, 3 go up. Villain is in BB. He played very loose aggresive poker and has been extremely lucky in this sat, pushing with mediocre hands and always outdrawing.

Anyway, long after he got into the comfortable chipstack to sit out and still win, he continued to shove EVERY hand. It was really annoying. Then this hand happened. After this hand he resumed shoving every hand.

PokerStars No-Limit Hold'em Tourney, Big Blind is t4000 (4 handed) internettexasholdem.com

Button (t34820)
Hero (t12230)
BB (t57790)
UTG (t7160)

Preflop: Hero is SB with 2[img]/images/graemlins/club.gif[/img], 5[img]/images/graemlins/spade.gif[/img].
<font color="#CC3333">UTG raises to t7160</font>, <font color="#666666">3 folds</font>.

If there is no evidence of collusion, there is nothing I can do about this? [img]/images/graemlins/frown.gif[/img]