Well it seems that man united supporters have that same excuse every single time they lose a match, as someone spectating from a completely unbiased view (i hate man united and chelsea equally as much
) everything the ref did seemed fine, every one of the man united and chelsea supporters will disagree with that though obviously.
There are the odd bits you have to watch twice or more to get a 100% opinion on them, and you have to remember a ref doesn't get to see them twice, from what the ref could see he did his job and he did it well.
While people say "such and such should have been sent off" if the ref isn't certain about his decision he won't commit himself to something as drastic and match changing as a sending off, somtimes it's better to let the game go on and just give them a ticking off.