Transparent teen agers...jeepers.
A number of Weathermen blew themselves up on accident while constructing bombs. I believe an ex-girlfriend of Ayers did as well, if memory serves. "Nonfatal" to others just means they're incompetent, not that they're innocent.
On a side note, one of our targets out here years ago was known as 'Abu Three Fingers'. It's not uncommon at all for terrorists 'engineers' to have blown parts of themselves off at work. Occupational hazards, if you will. Those folks aren't just misguided kids because they suck at handling demo.