I have to agree with Rich on this. It was pretty clear they were laughing at the idea of the shark scaring the swimmers and did not know a swimmer had been bit till a while later – when the laughing abruptly ended.
Were they assholes? Absolutely. But not as callous as you make them out to be.
And what are you basing the native California thing on? Are you implying native American? Or are you implying someone born in California? And where is it implied, suggested, or anything, and why would it matter.
I totally agree the fishers are jerks. But you imply a lot of stuff that isn’t there.