Let's step back, and look at this situation from a distance....

Customer seems to be a nice guy, but has severed realtionship with the electrician.

Electrician seems to be a nice guy, but has severed relationship with the electrician...

Both say nothing but nice things about the other guy...

Sorry, but my "lawyer alarm" just rang. Folks who so carefully guard their tongues are, in my experience, hiding something, and don't want to have their lawyers playing phone tag!

So, who are you going to believe? You can probably find others who have worked for, or hired, or done business with the electrician. They might venture an opinion as to the sort of guy he is.
Same for the customer.

Otherwise, some folks have been proper in their dealings with me, but other comments they've made have made me question their conscience and ethics. I have, in such cases, ever so carefully removed them from my life. As I see it, it is only a matter of time before they decide to "play" with me!

No one will talk? Remember the saying "birds of a feather flock together." Look at a man's associates. If his friends give you the creeps.... he's likely a creep himself!