Hotline1
Looking at the phase B fuse. It looks like they installed one end (the one not pictured) somewhat correctly. And used the tension form that knife blade to press the pictured end of the fuse onto the fuseholder terminals. It sort of looks like the blade was split, but I think there was just arcing and it made a carbon path to the blade. That would also explain why the silver end part is crooked, the black part of the fuse was able to straighten out after it overheated.