PA Mom,
Yes, those years are consecutive. From the 1st day they attend school, they have 5 years of eligibility for 4 years of competition. Only exceptions are religious missions, military duty or medical hardships. That applies to all NCAA schools, NLI or not.
There can always be an exception, but that is the rule of thumb. The NCAA also mandates progress toward a degree by X number of hours, declaring a major by X number of hours, etc. The timeline for competition is very specific. If an athlete has graduated with eligibility left, they must be enrolled in graduate school.
The only way I can think of a 40 yr. old Dad able to participate with his son (outside of the exceptions above) would be if he not previously enrolled in school.
I would do some investigation to prevent a change of heart too late.