What would you do?

[pb4ugo]

I sold a pair of Protek lipos that only had three runs on them. Yes, really three runs in my B44. Before I shipped them, I charged to 7.8 volts (they were 2 cell packs), though I didn't hook up my balancer. The buyer used the first one with success and had the second one swell and his esc (Novak Goat) fry as soon as he turned on the switch.

I feel very bad, but am not sure if I should accept any responsibility and offer partial refund. I never abused these packs in the three runs I put on them. I'm also concerned because he didn't actually do the charging, his friend did. I really don't feel in any way responsible and he hasn't asked me for a refund, I'm just wondering if I shouldn't for some good mojo.

What would you guys do? Also, what do you guys think could be the cause of the problems? Could over-volting the Goat from overcharging the packs be a likely cause?