Ditto, and my biggest takeaway from the series. If she were a child I get it. Yet, not only is she an adult, but he said he saw her around 5:30am "and she was safe." My first reaction..."why would she not be safe?" Perhaps he's adding protective words in hindsight, but he makes a point of saying he looked for her feet, and she was there. Not that he assumed she was in the bathroom which would be a logical deduction. Perhaps he did say as much but it was cut as not provocative enough.
Anyway, it's curious he went from 0-60 on the panic meter so early on. Especially since he knew she was out into the wee hours, and never stated he was concerned about that part. You could chalk it up to being overprotective, but no one was clutching their pearls about her drinking, in a nightclub, with what amounts to strangers...so it's hard to reconcile.
Regardless, she's not in the cabin...why go looking for her if only 30ish minutes had passed? If they had an early excursion I'd imagine he'd think she was already lined up to disembark rather than feel the need to find and remind her, and certainly not go straight to catastrophizing. I'm left wondering if something relayed by Brad to his parents about either he and Amy's conversation on the balcony, or something recalled from the nightclub prompted such a reaction. Then on top of that, her mother requests a voice broadcast at 7am when we're just past an hour. Now the family at least sounds exponentially alarmed. How did they know she wasn't social butterflying in another cabin, staff or passenger? The father being so concerned, and the way it was edited, sounds like he thought maybe she'd committed suicide, but "you can't let anyone off this ship" to me actually rings of knowing or assuming something else is at play. Some kind of intervention off-ship narrative might put pieces into place, but actual evidence would be needed to name any...organization as a factor in this disappearance.
A lot of sensationalism and just-so editing, but that's another post.