If you are saying that the distinction does not change the final result (how much money ends up being created) then that is a reasonable definition of "material". It still doesn't make MMM wrong.
Saggy's reason for calling the distinction immaterial is different to yours. He claimed the distinction was not material because the bank would give cash to the borrower if asked. If the bank had to operate under the assumption that everybody who borrowed money would withdraw it from their bank account then there would be no distinction at all. (Of course, if the banks had to operate under the assumption that everybody might withdraw money from their bank account at the same time then we couldn't have fractional reserve banking).
On the other hand, if crediting a borrower's bank account involves "
no money at all" then there is a very material distinction.