interesting hand from Turning Stone $300 tournament

I was just thinking about this hand so I thought I'd share it and my thought processes.

Blinds are 100-200. I've just doubled up twice in a row (both with 55, once AIPF against AJs, and the second time I flopped a set and busted top pair). I have something like 6-7k to start the hand, I think (my memory is fuzzy).

MP limps in and I have QQ in the cutoff. I raise to 700 and he calls fairly quickly. He's got about 3500 behind after the call, I think.

The flop comes down Ks Tx and a low spade. He checks, and I check. I talked this hand over with someone and they said they continuation-bet 100% of the time here. I don't, and I'll tell you why.
It's not so much that I'm worried about the overcard per se (I don't always check my big pairs when an overcard flops). It's that on this particular board, it would be easy for an aggressive player to check-raise me off the best hand. QJ and Ax of spades are possible hands for a limp/call and if I am check-raised I have a difficult decision to deal with-- am I ahead of a draw or behind top pair or better?
If the flop comes drier-- K73 or such-- I'm more inclined to bet because I have more certainty that I'm probably beaten if I meet a check raise.
So on this board I want to maintain control of the hand. If he did have a drawing hand and the turn bricks, he's got much less equity if he makes a move at the pot. I would rather exercise some caution and pot control on a hand where I may have the best hand but I may be raised off it, as opposed to a hand where I know I'm beaten if I meet resistance.
The turn is a low card and MP fires out 800. I call since I feel like I still have the best hand, particularly since I've under-represented it. I think a raise here both pot-commits me and drives out everything that doesn't beat me.
The river is the ten of spades. MP quickly goes all in. (This is the part where my memory is fuzzy; I remember his all in being for about 2800 chips but also an overbet of the pot, which doesn't jive since the pot at this point is 3300, and that part of the action I DID get right.)
Something strikes me as suspect about the bet either way, so I replay the hand in my head, to figure out what would beat me that would play like this.
A king would never shove the river; the worst card in the deck came out (making two pair into trips and completing the flush draw).
I've played the hand rather passively, so he can't think I'm strong enough to call a push if he has trip tens or a flush. He would value-bet me (and a push CAN be a value bet on the river, but I really didn't think it was here, given the way the hand played out).
So I decide a bluff is very likely. I study him for a few moments after thinking it through and notice he's leaned over the table holding his cards like he's getting ready to victory-rip them. That's a tell-- acting strong when you're weak-- and it jived with my logical analysis of the hand. So it took me about 45 seconds to piece it all together, and I finally called.
He said "nice call" and tabled A9o.
I busted him and ran my stack to about 11,000 chips. Our table broke soon afterward, and at my new table with the ante rounds starting I was able to attack frequently and maintain my big stack.
I rode it all the way near the end, when I got too out of line and made some questionable / bad plays to leave me short stacked. I finally had to resort to some desperation pushing and eventually lost when my J9s ran into AK. I finished 15th.

I just like this hand as an example of logical tells matching with physical tells, and how playing a hand passively can occasionally net you more chips than it would have otherwise.