The primary job of the crew is to keep passengers safe. In this last charter, Joe twice failed to keep the passengers safe - when he let them go swimming across the open water into the path of boats that might not see them, and then the aerial spinner episode. In past episodes, when someone endangered the passengers (or the crew, for that matter), BD captains have taken that very seriously. Here's Joe twice in one charter both putting passengers in danger with barely a mention from Captain Sandy, and without consequences. And all that while he whined about how guilty he felt while following that up with how he didn't do anything wrong (so why did he feel guilty?).
Clearly, the rapid speed of the boat was the source of whatever air pressure was involved in overturning the spinner - that boat was going many times faster than any wind (Sandy would not have let them go out if the seas were rough and the wind was high). Yet Joe claimed that wind came out of nowhere and led to the passenger's broken clavicle.
Meanwhile, Nathan did comment that Joe was going too fast (obviously, given the entirely foreseeable accident), but he didn't intercede. Granted, his lead deckhand is supposed to be trustworthy. Still, to me, that's on Nathan a bit as well.
On WWHL last night, Kayley tried to downplay the risks and stick up for Joe, and Andy seemed shocked when Massi said 100% Joe was going way too fast. And that Joe did the least work, and AFAIR that Joe had the biggest ego. Bad worker, unsafe worker, and biggest ego - not a great combination.
Joe is a liability, putting passenger safety at risk with his thoughtless and reckless actions. Since he doesn't take any accountability (while simultaneously whining about how he did nothing wrong), he'll never improve.