Wow Lisa that is a very good question and not one I have been asked before.
I don't know that I have an extremely straight forward answer but I will do my best.
Yes with raw food there is a chance of contamination to us from the raw food. The freezing stops bacterial reproduction but does not kill bacteria.
Definitely with the beard that is a concern. I guess it depends how much food he gets on his beard and how much he spreads it around the house.
One suggestion would be to clean his beard after eating although I realize that may be more of a task than you want to take on with every meal.
Another thought would be to cook the food and avoid the issue at all although more work for you once again.
I have also seen many of the chronic colitis or IBD dogs do very well on canned Merrick without any dry.
Hope this helps.