I've been following this very closely and that's my take also.
But Rassman's claim is very shacky. Since he was under water at the time. Gardner had a good take on what really happened. Essentially saying that when the mine exploded we all started firing which was SOP. Then ceased after it became obvious there was no enemy fire.
The thing that gets me about that whole incident is Kerry taking a powder when the mine went off, leaving the other two crews to handle the emergency. That even made the Washington Post, but the talking heads mostly ignored it.