My employer pays for my son's graduate school - question on if he is dependent

My son gets full tuition remission for his law school through MY employer.
Because this is viewed as a taxable benefit, I get the taxes withdrawn from MY paycheck.
I know he is no longer someone I can claim for child benefits, but I am wondering if he is still a dependent but he's right on the border of how they define dependents...
He just turned 24 Nov. 2024
He is a PT student at Law School
He works PT (earned under $40K)
But I still pay over 50% of his expenses: Due to cost of living in LA since my work pays his tuition, I pay his car insurance (since he just learned to drive and can't get his own policy until it's been a year) and I help with his housing costs (outside of my home).
Since I'm the one who gets hit with the taxes being taken from my paycheck proactively, should I claim him as a dependent to get the tuition benefit and beg forgiveness if I've done it the wrong way?