Kathryn, are you sure you didn't have the injection?
The only reason I ask is that I was told it's standard procedure according to AMA medical guidelines unless specifically requested not to be administered by the mother. I didn't realise I'd had the injection with either of my kids until I was told afterwards with Sean, and with Kate I had a little bruise at the injection site, so I realised I'd had it. They did it just as I was holding my babies for the first time and was completely unaware that they were doing it.

I'd say that if anyone feels it's important to them not to have it then it's their right to have their way.
Personally, I just like the third stage over and done with so I can get on with getting to know my baby.