I'd call as he's a LAG against an avg player i'd fold and vs a tricky player it would be close either way. To call you have to win over 65% of the time to show a profit so against the LAg I'd guess that's he's bluffing here at least half the time.

Also if he is lag he may have raised his flush draw on the flop, which points further towards a bluff or weaker hand.

I call Mr. Lag