His rant was aimed at Chuck Lorre over comments he made about Sheens lifestyle. Lorre places a Vanity Card at the end of every episode of every show he produces. Many are censored before they hit the air, but can be read on his website. Many are funny but alot are really weird. One of his recent cards made direct comments on Sheen's lifestyle. He took aim at Charlie, who is pretty unstable, which was why Sheen went off on him.
Read the cards. The censored ones are pretty interesting.
http://www.chucklorre.com/index-2hm.php
Interestingly the card from last nights Big Bang Theory says he's taking a break from his essay type cards.