The combination of me being an argumentative twat and wanting to savour the Irish gold medal had me watching this footage again today.
Pay close attention from about 30s onwards (overhead and underwater footage) and tell me again that "nobody is using their legs" because it seems pretty clear to me that Wiffen is using his legs a hell of a lot less than basically everyone else.
I barely know anything about swimming but our Belgian commentator mentioned straight away that Wiffen stands out because he doesn't use his legs the first 700m. Didn't say that or mention it again about any other swimmers in that final.