The whole 'I'm from Delaware and we do things different here' thing is silly, and you can knock it off. Delaware isn't that different. It's not on another planet.
A couple things wrong here.
First, this is all a moot point, because there's no indication the man checked for viruses or anything like that. By his own account, the computers were brought in for water damage and sticky keys, and the repairs only cost $85. Those are simple fixes that literally anyone could do, and they don't even require you to turn the computer on, much less inspect its contents. He was not paid to run the system or test it or anything like that, nor did he say he did such things. That is something you're making up, whole clothe.
Second, even if he had, those systems are automated. The idea that checking for viruses and running malware requires you to painstakingly read over and watch every file on someone's computer is ludicrous. I've ran this kind of software. I've seen it run. It does not require you to look through someone's personal information. It wouldn't be very efficient if it did, nevermind the legality.
Let me ask you a question - would you have your computer repaired by a person knowing that he might, if you fail to pick up said computer for whatever reason, start riffling through your personal information? Credit card information, your search history, emails? Because I seriously doubt you would. Why would anyone ever let their hardware be repaired by anyone if they thought that was even a remote possibility?