Would Hank have accepted the therapy money?
Considering that Marie kept it a secret from Hank, expect he would have resisted taking Walt's "gambling" money from Walt. Perhaps he would have caved, as it appears it was this therapy that got him walking again.
When Walt asked why it had to be kept secret, Skyler reminded Walt that he too did not want to take "charity" for his cancer treatment. So would Hank's ego have him similarly at fault, in comparison to Walt, if he were told and turned down the money?
And once Hank discovered Walt was Heisenberg, and that he received Walt's money for therapy, is there any part of Hank that realizes he wouldn't be walking if it weren't for that money?