30/15 isn't really that much of a lag. If anything, he doesn't raise enough of his hands. Sure, a bet from the cutoff is likely to be a steal, but unfortunately, at 15% PFR his range of raising hands had you dominated. I'd be way happier if it were 95 of diamonds or 85, or hell, even 92, at least he's less likely to pair up the same card and outkick you. I'm nervous if I hit that jack but I'm only playing this after the flop if I hit 5 or a jack or a flush draw ... I don't see why you bet this flop, much less called a raise.