Antonio re: "any other proof"

My question is "Proof for what?"   That single person is the RC.  RRS 29.1 says ".. the RC shall ...".  

It's not an issue of proof.  It's an issue of obligation.  

There is nothing in the rules that require anything more than RRS 29.1, A5 and A10 for OCS.  All other things an RC might record for their own records is up to them. 

Other than that, I'm not sure what you are asking.  

Can we not add the evidence or inescapable reality of physics and math to our consideration of evidence presented?
The masts are ~10m above waterline, centerlines at one boat length between chines claimed to be ~10m apart. OP said contact at masthead. The contact almost can’t have been masthead to masthead unless both boats were healed 60 degrees toward each other. W’s masthead must have been very close to above L’s hull before L lost their main sheet. W’s masthead must have contacted further down L’s rig, as W would be healing more than L. 
I guess the question really is if there is a point at which a boat’s sudden heel to windward would make them at fault. Say a laser which can roll further and faster than the J in OP’s scenario. Or say a narrow hulled moth, foiling or not. Maybe a near capsize to windward, saved by a tiny margin, causing contact the same as in OP. Would it be different if caused by a lull in the wind, responded to better by W than L, making it still a boat handling error, same as dropping the main sheet. 

Jim Champ Reply to: 22039 - John Quirk: furthermore, in CASE 50, in the first sentence, it actually uses the term "genuine and reasonable apprehension" (this of course a standard used by courts with applications for an arrest in connection with non-bailable offences), and in the second sentence 'reasonable doubt' (again, a well-tested legal / court term). Quite some complexity for a competitor and PC to become acquainted with :).

And I appreciate it.

I never called you a blockhead.