No. Just no. In no way can they be held liable. They sold a battery. If the consumer used it in any manner other than its intended use...well, he is SOL.
I haven't shopped in TehShack in a long time, but I'm going to assume they've covered themselves with the standard legal boilerplate for batteries that limit their liability to the cost of replacement of the device they were used in. The only way they might be be held liable for more is if the sales person was "Oh, these'll work fine."
The line "After buying the proper batteries" irritates me to no end. If they were the "proper" batteries, they wouldn't have blown up.