Or the respect you give them. In this case, zero.
I'm not the one who got in trouble or the one who didn't respect a marshal boat, but I also spend about 100 days more a year at big events than you do, and I know what people are likely to do once at a big start. Most spectators don't check any official documents, most don't check notices to mariners, and a surprising number will do the stupidest thing they possibly can. If an event director doesn't plan for that, they are not doing their job.
And if a professionally crewed multi can't plan for a spectator boat to do the stupidest thing, perhaps 20 knts means not doing their job