Actually, those stuarts of mine shot the tank earlier (and then were destroyed before my men got close). I was hoping that the hits might have caused light damage to the hull which might make it easier for small explosives to knock the tank out.
And yea, I think after awhile the men inside the tank should surrender. If your the only friendly unit around, and you cant move your pretty much as good as dead.
It's kinda funny because I just played another game and the same thing happend. Although it was a panzer IV and not a tank destroyer. Also, I was only able to shoot grenades at it. The second grenade hit imoblized it and I sent what I had left of two platoons behind the tank but with only 2 turns left in the game my infantry couldn't do much. (To bad my piats got knocked out earlier, I'll have to remember to keep one back.)