I can not imagine that a jumped tooth on a timing set broke a cam.
How much play is to much?
I do not know what the specs are.
I would just replace it since you are that far into it and it is fairly cheap.
http://www.roverparts.com/Parts/9009B.cfm

 

Here's a couple of pics of the chain. I know the timing marks don't line up yet, the reason for this is that I marked everything as I took it apart and then put it back the same way. It seemed a little strange that it went back together just one tooth off. Possibly mechanic's error, possibly jumped a tooth - thus the question in my previous post.

 

I dont know man.
It could have jumped a tooth.
There is no reason for a mechanic to be in there though unless he is replacing the oil pump or some such.