I don't think there is anything wrong with validating information presented as being from your office is or is not correct.
Basically the employer is just making sure the employee did not forge an excuse slip.
Just putting the date on the excuse, which should have already been on there, doesn't mean anything.
In fact most excuses advise to contact the office it is from for further information. Obviously you wouldn't give out anything you weren't authorized to give out but validating they were seen or they were put on limited duty or that they can return to work on a certain day, whatever the note is for, is expected in a case where it is questionable for any reason.
Providers need to know if pts have altered documentation as well and should welcome these calls.
My thoughts for what they are worth,
Laura, CPC, CPMA, CEMC