When you had it puff - what were you doing - high speed runs? Did you take it easier this time?

If you were running about the same amp draw as when it puffed initially, then ambient temp may be the diff. How much cooler?

Thats not enough voltage diff to worry about. I've read that the hardest thing on a lipo is running it to the lvc - beginning to think thats what's going on here, if you had run it to the same voltage as the initial run, prob would have had it puff again and get hot.

Def wouldn't run it to the lvc next time out just to check. Maybe you need to raise lvc?