There's substantial evidence that he wasn't driving the boat.
As for the selfish. "Concerned for getting himself intoxicated." Making it sound like he was a drunk, coke fiend that went out partying non stop. This sounds more like a case where a guy was struggling mentally after an argument and turned to drugs/alcohol to help. Stupid? Yes. Selfish? No. Traditional selfishness typically involves the guilty party getting any sort of benefit from the situation. He wasn't.
I didn't intend to infer that using drugs or alcohol to deal with your problems is stupid or selfish. I'm saying that using drugs and alcohol and then getting on a boat in the middle of the night is stupid and selfish. I'm not going to tell anyone how they should or shouldn't use drugs and alcohol, it's their decision obviously. But it should be pretty widely accepted at this point that driving a car or boat while heavily inebriated isn't a bright thing to do and given the circumstances was absolutely selfish.
To me being selfish involves only considering oneself with no thought for how your actions may affect others. In this case, Jose decided to get drunk/coked out and get on/drive his boat in the middle of the night. He put himself in an extremely dangerous situation with no thought for how said situation may affect those that loved him.
Whether he was driving the boat is kind of irrelevant too (although I haven't read anything stating there is reason to believe he was or wasn't driving. Wasn't aware they could determine that). It was his boat, and based on the texts it appears it was his idea to get on the boat despite being urged not to by friends.
We can remember Jose fondly while also letting this be yet another tragic lesson of what happens when you drink and drive, or in this case boat.