Likely he did something to trip PATS which is why it is flashing like that. You can turn PATS off via a tune or you may have to take it to a dealer to get it turned off without one. If you are having a shop do your work and they tripped PATS they should be the ones paying for it honestly.
2000 Mustang GT Steeda #0048 34k miles. 99 Cobra 4V swapped, FTBR IRS swapped, exhaust, tuned by James Gordon.
Just because I give you advice, doesn't mean I know more than you. Its just means I've done more stupid ****.