For MeiMongo (at least): "Sorry about your busted weiner."

For Brady Giovanni: "Sorry I blew you up."

For Jian: "Good luck on your Immune Reaction Expirement!"

For Randy: "Sorry I left you to die. Well, not really sorry. I needed to live."

etc.

I'm sorry about your arm. I needed a hand...

For anyone: "Are you injured?"

In deepest sympathy for your junk.

Martin Brewbaker: "Sorry to hear of your axe-ident".

"Your species was delicious delicious delicious! Deepest sympathy, The Sklorno"

For Athanas; "Sorry I kicked you in the nuts."

BigJohn

Ha! That would be from CB, but I don't think it would be very sensere. He was laughing like a maniac when he did it.

Here's a multipurpose one:

Sorry about your (insert: body part, family member, pet, etc etc...) I sincerly hope that it can be (found, reattached, put back together, ect, ect...) Your (friend, enemy, teammate, etc, etc...) 

I like this one!!!

"Thinking of you. SMOOCHIES!!"