limit hold em hand. smart play?

[P. Bibby 0]

Hi all.. I've been thinking a lot about a hand my friend played recently. It was 3-6 hold 'em, and there was a straddle bet on board. (why the hell people do that I'll never understand). First player after the straddle raised to 9 dollars. My friend had 8-8. He thought the raiser was on a weak hand, so he re-raised to 12, drove everyone else out. The first raiser called. Flop brought an 8, and his trips held up. On one hand, if he the initial raiser has K-10 or something, it's a coin toss. A re-raise may be the only way for 8-8 to win the hand. But if that first raiser has 9-9 or better, my friend is 4-1 dog. Results of this flop aside, was isolating against the initial raiser a play with positive EV? :?