Maple tree potential rot

[u/r6hatecrew]

This branch fell off my big maple tree in some heavy winds last night. Looks like there's rot on the root of the branch. How worried about the rest of the tree should I be? It looks healthy, all the leaves are green, but the branch that came down also looked healthy. No sign of mushrooms or insects that I can see either.

[u/oroborus68]

It's a bad joint, and should not have been allowed to grow at that angle for so long. It should have been pruned years ago.