Son graduated in June 2018, employed Aug 2018, ended up covered under 2 HDHPs at end of the year with his own HSA. HSA not allowed? What does he do?

Not sure whether he can still use turbo tax to file - what does he say on insurance - family or self - was on both, and pay the penalty on the HSA contribution.  He is keeping 2019 contributions low and will not exceed a total allowable for 2019 with the 2018 overfund in mind.  Since he was a full-time student and we were covering his expenses until August - we can claim him as a dependent. Our company didn't provide the details that we needed to remove him from our HDHP in time.