Over a year ago a senior HR person (3 levels higher than me) was bought into my organization. I had dealings with him very soon after he started over an issue he was involved in sorting out and instantly thought I recognized a potential friend in him (not romantically he is openly gay). A few months later a redundancy programme was implemented, I had seen it coming for a long time so wasn't surprised - it soon became clear that was why he had been brought in as he was experienced in doing this and was leading the programme, I was in the pool.
Lots of staff immediately nicknamed him the Grim Reaper, joked he doesn't have a shadow etc and even though redundancy situations are horrible I think it was all handled as well and as sensitively as it could be.
I'll get to the point, he retired last week, he was only there a little while but rank/role and the reason he was there seemed to make it impossible to be too friendly. In the admittedly limited dealings I had with him he seemed like a nice warm man with a good sense of humor. Now he is just a bloke with no power over my future/position/pay etc would it be weird if I send him a friend request on FB? I just always felt I recognized a potential friend and was really sad to hear he was leaving, it felt like a missed opportunity.