I wouldn't necessarily "hang" a first-time offender, but I'd definitely be wary, and cautious of how much I'll trust them in the future. Personally, I'm not a fan of making statements that say "I'll never again buy/use such-and-such a service or product". I might be willing to consider using their software again in the future. (I'm speaking in the context of this argument, since I've never actually used ImageGlass.)

Regarding crime, there a lot of behaviors that aren't legally defined as crimes, but are still objectionable (sometimes very). As such, there is no court to prosecute them with the legal system's presumably objective processes, so it's up to the general public to make our own assessments.

Finally, I'm curious as to your level of tolerance to questionable, unexpected behavior by software developers. Maybe not this one, but I wouldn't be surprised if there were certain actions by software developers where you wouldn't tolerate even a single offense. In any case, our differences regarding tolerance to questionable behavior is why we're all discussing this incident anyway.