Maugh, for a beercan race I agree.
If you go and play with the serious boys in grade 1 events, it's tough luck.. But then it's all about going fast, so if they can get away from you faster they wont put you into a "checkmate" situation like that. If they can do it while not slowing down, you better keep clear.
Looking forward and thinking two moves ahead will usually keep you out of such trouble. Shouting about turns etc. is uneccesary, a simple "protest" does it.
The described situation sounds like the guys on the I20 did not think far enough forward, even if the Hobie was in error.. In their defense, it's easy to sit here in my armchair and have 20/20 hindsight.
If luffed up like this, I would have dumped the main traveller and let the spi flog. That will usually save your day at the cost of some wear on the spi.