That doesn't mean it doesn't, can't or won't happen! I have seen them catch fire with much, much less provocation than how you've abused yours.. It is NOT NOT NOT pretty and it can happen in an instant, with no time for you to realize or react. LiPo fires are no joke. They're violent. They can explode like a bomb. They spit and pop.
You have been very lucky young sir.

If you at any time notice a cell has swollen, or if you notice your cell getting warm (even without swelling) when you don't expect, get it as far, far away from you and anything you like still owning as soon as you can. like.. RIGHT NOW soon.

Some of you might tell me this is a bit extremist, but I like having all my skin on my bones.
Treat LiPo's like they're a loaded gun, IMO. Don't take risks that can end in serious injury.

EDIT: Don't be scared of them, CoolDude! I don't mean to give that impression! Fires luckily don't happen very often, and a swollen cell doesn't necessarily mean it will catch fire or anything.. Look at what Eskimo says about his. Just don't be flippant about it is really what I wanted to try to impress. It might not occur frequently, but just don't get complacent about the possibility and you'll be fine. 

Sorry to here that, hope you can get it up in the air soon.....

They do make hard case lipos designed for non-flight applications.  You should also consider LiFe batts: they also are more impact resistant, tolerate deep discharge, and less voltage sag. They are heavier which is why less people use them in flight applications but they are great for cars/boats/etc.