Wow where to start. LOTS of good stuff so far.
First the role of the tactician. In this role he's also a coach, but you really have to do one role at a time. Ideally as tactician, a few minutes before the start they should tell the skipper where and why they want to start on the line, how important that position is, and where the boat should be a minute after the start. Then ask the driver how much guidance they need to make that happen. Ideally the skipper says ‘None, I got this'. I'm sure this is not how it went on this day; this driver needs lots of second-by-second instruction, being what I call a 'remote control driver'. This is OK for coaching, but you need a much less agressive starting strategy. Which they did not have.
For some reason they were using a so-called 'Vanderbilt Start', which has you reach off for a minute 2 minutes before the start, tack back and come back to the line, hitting at the gun. While reasonably safe for a new skipper mid-line, it is VERY dangerous to do at the boat end, as being overstood by any amount puts you at risk of barging.
So thats what we got. A big boat, an inexperienced driver, and a tactician busy playing with some app on his phone. As they come in, it's clear that they are overstood, and are in fact barging. As he talks to the driver, he should note that it's not a conversation. Thats bad. It means that she's not processing anything, just trying to do what she's told. At the end of the day; it's on HER to decide where the boat can go. But's she's not capable making that call.
At 0:46 is the real decision point. ALL boats to leeward have rights, and are coming up. Notice that Blue is still reaching; her mainsail is way out. He asks for up, but should really be looking at this as his last chance to get out of Dodge. But he does not, he asks her to come up to make room, but she freezes, probably rightly worried about the RC boat. Why not bail? Remember he is a paid PRO. And you don't get asked back when you deliver 3rd row starts. And you'r a paid pro on a kick-ass J/122. You don't lose the start to a Catalina with a bimini and kayak on the rail.
At 0:52 they are committed, no bailout now. Someone mentioned the person in red leeward could have been talking about other boats. Not their job. They're headsail trimming; his only job is to watch the telltails. All other boats will start fine.
At 0:54 Camelot comes up hard. Who knows why and who cares; it's totally in her rights to do so. Windward boat shall keep clear. Here the driver needs to react instantly; but does not. Remote controlled. She's waiting to be told.
At 0:56 he asks for up-up-up, and she grinds the wheel. Not much happens, the rudder probably broke flow and cavitated. And in a powered up reach, a mainsail ease would have taken pressure off the back of the boat and helped the turn. It's clear that they are not going to be able to keep clear.
At 0:58 the tactician makes the worst decision of his life, he tries to prevent 40,000 pounds of boat from touching.
As I see it this was all on Blue. Camelot of course came up, but she was leeward. And RSS#11 is very clear. 'When boats are on the same tack and overlapped, a windward boat shall keep clear of a leeward boat'. And before this, RR#12 was in play 'a boat clear astern shall keep clear'.
Because of this (she had ROW the entire time) Camelot is not required to give Blue time or warning to keep clear. It's her responsibility to stay clear regardless. And any 'proper course' claim cannot factor, because Blue was windward (RSS17) and it's before the start and there is no 'proper course' at that time anyway.
I re-read the comments and lots of people picked up on the human interactions, and/or the lack thereof. I think that's the sad key to this story.