Hello, Hung Hoang. The review explicitly targets instructor Chad on a personal level. Micah and Chad are combat veterans and passionate instructors, with over 15k safe dive experiences. While many customers understand their dry sense of humor and straightforward military styles, some may interpret it differently. The DSD quiz is a PADI requirement to help the instructors evaluate how much knowledge the diver has absorbed. Instructor Chad did precisely what he is trained to do. The divers were distracted by their phones and ignored Micah's dive briefings. When tested, it was clear that they didn't remember. The instructor had to redo the briefing. All 8 divers completed the skills, but only four went for the second dives. One diver hesitated on the ladder, which is unsafe for lingering. Instructor Chad had to say, "If you don't come now, you may need to stay on the boat." Based on your summary, the Ring footage, and crew feedback, the one-star review doesn't reflect the actual event."