Peter looks like he's about to start explaining that he can absolutely be responsible with this kind of device but shuts up when it comes out that Rocket's idea of responsible is much much different than his own.

"So it's not exactly stable, then." Peter frowns. There ought to be a way to properly ensure that you'd only get a flash rather than the risk of a full scale explosion. "Couldn't you cut the power supply by about a third and re-sodder the circuitry? That would put a hard cap on just how big of a bang you'd get I'd think.."