I have a boat, tight villain mini bets turn with flush on the board

[NYWalker]

Legends of Poker $540 NL.
I was very active at the table. Villain is a tight player. We played a lot and he made good EP folds to my LP c-bets a lot. A few hands ago, I raised the button with As6s after he limped from CO. The board showed two spades, he checked, I made a ridiculous big push (3K into 400 pot), he folded and I showed him my cards to him.

This hand, 50/100. utg limps, villain (3K) limps in from the button. I complete SB with A4o. BB checks. Flop 4h4d5h. Check to him, he bets only 200. I call. BB, utg folds. Turn Ah. I check, villain bets 200. both of us had about 3K behind.

???