Magic Lantern is designed to be as simple as possible - you stick a file on a memory card and that's it. ML is 'marketed' as something that 'just works'. The developer needs to understand that the people who'll use it are, essentially, IT newbies who won't always understand the need for backups, understand what a roll back is, and won't follow instructions. That means they won't necessarily understand the fix, and they will believe a message that says their camera is bricked.
None of that means he shouldn't have played a joke on the users, but it definitely means he ought to have thought it through more. And, as you say, he should have had a much better response to people's understandably somewhat panicked reaction.
None of that means he shouldn't have played a joke on the users, but it definitely means he ought to have thought it through more. And, as you say, he should have had a much better response to people's understandably somewhat panicked reaction.