I am so sorry for your loss. I also am a black cat owner, and he gets the full barrage of shots as he's outside for a couple hours every day. Unfortunately, with vaccines, this is always a risk. There are always risks with any medical or veterinary procedure. But it should not sway anyone from getting a pet (or a person!) vaccinated if the situation warrants it -- the benefit outweighs the risk. However, I am so sorry, and it is terrible that your pet had to "be the 1" in 10,000, though!
Also, if one gets the FeLV shot, make SURE they do the "FeLV TEST" *first!* -- this should be a day or two in advance.