Do we have a case - disability discrimination, Civil Service Law violations

Hello - I think my husband has been discriminated because of his disability.
He is a competitive class worker laid off from CUNY after 16 years. He had to take two FMLAs in the past two years. In Feb 2018, after returning from sick leave he was told to request transfer to another campus, since they wanted to “remove the line” from payroll.
In May 2018 he had hours changed to those of the outside contractors, i.e. was forced out of performing his regular tasks and duties.
In June he was again told to request transfer to another campus.
Union said that was not the procedure, which he conveyed to the employer.
A month later he got a 30 day termination notice dated July 12 , with no options offered. During that same time a provisional opening for his title popped up at another campus, posted 7/17/2018, with closing date of 8/7/2018. There were also few openings in titles he would qualify for (with lower pay) which he was never offered.
On Aug 6 union advised him to put in a request for transfer for the open position at that campus, which he did. On Aug 8, employer cancelled the meeting with Union for that date, citing the matter “now being with the other campus”.
He was sent for an 'interview' at the other campus, and was not transferred/hired. So he has been unemployed since then.
I was wondering if we had a case for disability discrimination, retaliation, and for Civil Service Law violation by CUNY. He is the only laid off person in CUNY, there should not be any competition for the open provisional position.