Banks and credit cards have a great many security features that were not available in the past.
If an unusual charge goes through on one of his credit cards or ATM, or a check is written for an unusual amount, the security computers jump right on that.
The bank or card company will call him or text him immediately, and in some cases will block the transaction while it is happening.
The major things to watch for are new credit cards, or a new bank account, or a loan that is not his.
If someone uses your Dad's credit card or bank checks, your Dad is not liable as long as the issue is discovered and reported in a timely fashion.
If someone takes out a loan or gets a credit card in your Dad's name, your Dad has no liability, but it might ding his credit report for a couple months while you clear up the problem.
I advise watchful waiting for a couple weeks before you do anything.
Maybe give the solar salesman a call. If he knows one of the children is paying attention to this scam, he will look for easier undefended victims.
Thanks, yes that has happened a few times with me after making big purchases on my credit card they locked it until I called to confirm. Well that’s a relief. Thanks