Thanks Charlie. I’m not sure I was quite clear enough really - my bad.
If the contact is REALLY minimal, then it’s not a foul under either ruleset. The difference is when contact is meaningful but not dangerous. For example, let’s imagine that the play doesn’t quite qualify as dangerous but is enough to knock the player off balance or otherwise inconvenience them from getting on D immediately. It’s a foul under both USAU and WFDF, as play has been affected by the contact. But under USAU, the block stands - we stop play, allow the fouled player to regain position, but we don’t give them the disc back. Under WFDF, we’re basically saying - that’s too close for comfort, and we want to discourage it. Meaningful contact related to the block means you shouldn’t have been bidding in the first place, and so your block doesn’t stand.
Really, it’s about following through on this idea, which is in both rulesets in some form: “It is the responsibility of all players to avoid contact in every way possible.”
If I can’t get a block without contact, and I do it anyway - causing contact - then that block shouldn’t stand. Otherwise the rule above is not being properly followed. We can’t reward someone for breaching the ‘avoid contact’ rule.
It’s easy to think that WFDF are punishing someone for making contact, but really it’s not that - that contact should not have happened, and if it hadn’t happened then the correct outcome is that they wouldn’t have got the block. It’s not a punishment, just the correct outcome. Under USAU, they are rewarded for a bid that resulted in contact.