Morgans wrote:

It seems to me that charges could also be filed, for letting a non pilot
manipulate the controls. Since the 70 year old is not a CFI, the student is
just the same as a non pilot, and if he (the student) was PIC, he would be
in violation for taking a passenger with him. Both of these are against
regs, aren't they?

The student cannot carry passengers and so cannot serve as PIC. There is no reg
against allowing non-pilots to manipulate the controls.

George Patterson
"Naked" means you ain't got no clothes on; "nekkid" means you ain't got
no clothes on - and are up to somethin'.