The original question - can it be reused reliably? NO.
If you were industrious, you could check the voltage of each individual cell under load. If lucky, you'll find just one that was significantly lower than the other 4. Then just cut out the bad one, rewire, and use the remaining. But...I'd never trust that pack for flight, and would relegate it to use in bench testing only, a kids toy, or something like that.
If unlucky, more than one tests bad....