Sick call...

Holy shit, I don't know what made me call this... something just told me his shoving range here was air alot.
I actually kissed my mouse when I called... as in kissing my money goodbye.

weaktight | Hand | 99 - $0.25/$0.50 No Limit Holdem

So Villains has been playing kinda tight preflop, but kinda aggro post flop. He hasn't really been floating me a ton, but if he takes a lead in a hand, he usually 2-3 barrels. I noticed this because mainly I've been card dead and I've been trying to float him. But everytime I try, he seems to 2 barrel. I think I successfully floated him like twice through the session of about 50 hands.
So Here's my hand analysis.... which I'm not even sure makes sense.

Obviously his preflop raising range his huge, and his preflop calling 3bet range isn't small either. I discount AA, KK, QQ, JJ, AK because we've been playing pretty aggro preflop and I definitely expect him to bet those for value instead of slowplaying. I may even throw in AQ.
On the folp. I rep medicore hand, therefore he bets his entire range. I
On the turn, nothing changes. I rep mediocre hand, he bets his air, Q10-QA, monster still. 7x and 8x are also discounted because although his calling range is pretty wide, i don't think middle suited connector in there.
On the river, an ok bluff card came for me. Had I shoved this, I think I would be able to get him to fold weak Q. But i thought i really didn't play this hand like a draw. I think that he would think that I would definitely bet the flop with a nut flush draw. So there's nothing I could do but play my cards face up.
His decision is more interesting tho.
So far, I've repped exactly what I had. Probably QK, or QJ type hand and some lower pocket pairs.
So, if he value bets thinly, he might bet Qx.
He would still bet his monsters and flushes.
But what about air? If he'd been barreling as like he was doing the previous hands, this is a GREAT bluff card for him. In his eyes, I shouldn't be calling this with anything less than QK.

So when he shoved, I don't think he's doing it with just Qx, cuz I don't think he's good enough to bet that thin. After all, this is 50NL. I think he would check those, scared of the flush draw.
My decision ended up being, what's more likely,
a) He has flush, or set
b) He has air, and is barreling just like before, to get me off of my faced up hand.

I decided on b.