I would not have folded. The texture of the flop is such that a pre-flop raiser will often will not have been helped (low cards, and only the 6 improves his hand over yours). Sure, he could have AA-QQ, but those are the only 3 likely hands that beat you right now; in light of his very loose stats, I think more times than not he does not have AA-QQ. I think it is more likely he has overcards, probably Broadways (also note: there are more combinations of overcards than of AA-QQ).

I have called down after Villain raised the flop.

Edit: I think a very wide range of hands from a very loose player like this will cap pf and not slow down on the flop: AA-TT. AKs-ATs. KQs-KJs. AK-AQo.