there are 2 things to be signed (Score 1)

Also, keep in mind that the agreement he has with
his former company is that he must sign over the
rights to the patent to his former employer.
nothing in his agreement forces him to patent
anything!

Therefore, he'll be asked to sign 2 things:

1) The patent app itself. This is where he should talk to his former company's patent attorney and work to get the patent disclosure itself correct.

2) The rights to the actual patent, assuming it is eventually awarded. This must be notarized. This one he absolutely must sign to honor the agreement with his former company.