I'm with JB, Flaming Turnip and Liv. Seriously. This sounds like two grown women in an 'one-upsmanship' battle. No one really ever wins.
Take a deep breath, and then take a second, or third. Arguing with her to prove you 'know' your son better is just going to come across as immature, insecure or both. In the big picture, does it matter if she needs to think she 'hears' him saying those things?
She's a grown woman.... let her wear shoes. One person wearing shoes in the house shouldn't be a big deal unless she's tracking in dog poop. Please believe me, I wear shoes in my house *all the time*. My feet stay warm and I feel better and happier that way. Why is this an issue? I just can't picture one woman tracking in so much dirt that it should cause a meltdown.
Please believe me, in the grand scheme of things, this is not worth confrontation. Save confrontation for things which are truly earth-shattering, like feeding him peanuts when he's allergic. I think this is more to do with your husband not having separated from his mom. If that's the case, couples counseling will get you much farther than being mad at her. Don't misdirect your anger because it's easier than dealing with him.
Oh, and maybe get some different childcare (if that's the 7-8 hours a week he spends with her) if this is killing you... if she is providing care, you do need to let them have their own relationship.