That begs the question of whether the unorthodox notation is a catalyzer for the results he gets, just a coincidence, or if just thinking differently in general is the reason for both. =)
I am strongly against prescriptivism telling people that a bad translation that makes no sense is correct. I recommend "assuming the conclusion" as a correct name.
You'd think something as straight forward as (boolean) logic would converge on a standard notation. But I'm not familiar with the mathematics field to really criticize this. Regardless I found it to be a large barrier-to-entry which over complicated something when I was hoping to find direct analogies not needing constant 'translation'.