Normally it's a year from the time of the medicals and you don't have to move right away. He can go to Canada and land, give them a Canadian address to mail his PR card to and leave again. Whoever is at that address, friends, relatives etc. will get the PR card and mail or fed-ex it to you. If you don't have an address to get the PR card mailed to, just explain that he is not staying this time since you are not quite ready to move yet and he will give an address and get his PR card once he comes to Canada to stay.
So did you mean if he did his medical June 4, 2009 and sent it with the application package, then PR visa to land will expire June 4,2010 ?