Without seeing it for myself there's no way to tell for sure what connection was made or broken where. However if an arc
happened and then you could read voltage where you couldn't before, then either something melted or something arc
welded. Either case can be bad if left unattended. The main danger
is if something arced by barely being bumped, then it could happen again when you're not there, resulting in a fire. If you're going to be gone for a while, disconnect the suspect circuits until you can be there to track down the culprit. Or make sure your insurance
is paid up and cross your fingers.