Sorry, chaps, but I agree with practically none of the above. The point here, to my mind, is that the yellow flag doesn't simply mean 'void race', it means stop riding, and Rule 66 actually says that a race is void when the yellow 'stop race' flag is waved. In other words, it's a universally-recognised instruction to stop the race at once.
(Case in point digression, which I'll agree isn't entirely comparable: some years ago, a neighbour of mine drove out around midnight to collect his teenage son from a function in a town about ten miles away. On the way there, he found a lot of standing water in the road, and decided to come home by a slightly different route. On the return trip, they met temporary lights, set at red. After waiting what he thought was in unreasonably long time (CCTV subsequently established that it was about three minutes) he decided the lights were stuck, or out of order, couldn't see any headlights at the other end of the roadworks section, and very cautiously crossed the lights at about 10mph.
And got broadsided by a 4x4 coming across a green light from a road on his left. The lights were actually 4-way control, and the road on the left wasn't visible from where he's stopped. His son, in the passenger seat, was in hospital for about eight weeks, and only a couple of spinal millimetres away from spending the rest of his life in a wheelchair).
What I'm saying is that the jockeys may have thought they knew better than the flagman, but you can't ignore a stop-sign just because you believe it's displayed by mistake. They assumed the problem concerned a damaged fence, or maybe an injured horse or jockey: but an old mine-shaft might have opened behind the water-jump, or a nutter might be loose in the enclosures with an AK47. You cannot take it on yourselves to decide that a no-exceptions instruction can be blindeyed.
I believe that the BHA were right to impose the ban (and also right to pay the race prize-money, though that's a subsidiary issue) simply because an authority has to send the message that rules - here notified by flags - aren't matters for personal interpretation. Equally, when the appeals are heard, it would be crass to impose maximum penalties. But you can't abandon the principle, and a lot of the criticism seems to me straightforward anti-BHA knee-jerk.