I ran into the same thing on Sunday.
Helping a buddy pull his subs and amp out for a trip. When I went to disconnect the fuse I found it melted through the plastic holder and one of the wires fell out of the lug when I picked it up.
What was funny though - the washers on both ends of the fuse were melted as well as the insulation on the wires. The fuse never blew. Mini-ANL 150a. Buddy said he thought he smelt something burning?
Anyway, this was obviously caused by the loose wire arc.
Think this could have happened with any brand.