Fired While On Approved Leave

I’ll try to make this as short as possible. In late 2022, I found out that my wife had been having an 8 month long affair. She was sending pictures of our three babies to this man, FaceTiming him with our kids, and even took our two year old daughter across state lines to meet him. Needless to say, this was devastating and sent me into depression. I decided to stay and try and reconcile. While in that process, my depression got worse and I decided to check myself into the behavioral health hospital for five days. This was January 2023. As soon as I got out of the hospital, I asked if I could go on administrative leave and they said yes and gave me two weeks. I started to ask to come back to work just 3 days later. The answer I got was they were working with HR to get me back and they’ll update me when I can come back.

Two weeks go by- I’m asking multiple times a week for an update and get the same answer. At the start of the third week, I get a call from my boss thinking she’s going to say I can finally come back. Instead as soon as she answered she said “just so you know I have HR on the line with me”; and then the HR rep went on to fire me. They said for those two almost three weeks they were “working with the lawyers to make sure it would be legal”. Is what they did really legal??