Awww...poor little guy...I'm glad he's improving and that was really nice of you to share that as that subject comes up here sometimes. I hope he makes a full recovery.
On the potty training...I am no help - one of mine trained in a few weeks - my other took Months...but he does sound like he knows he had an accident...Cheri my youngest NEVER looked guilty
maybe after all he's been thru it's just something that will work itself out ?