A combination of the first and third. Be honest that he botched at least 1, likely 2, coverages that directly led to TDs, but also acknowledge that one game of issues isn't anywhere close to the stratosphere of projecting what he will look like a week from now, let alone years from now.
We see similar things in week 14 and it's been happening since, then the red flags are going up. Realistically, it'll never get to that, because if he's botching coverages like this for a few weeks that are leading to TDs, he won't be playing much, so it'll work itself out.
The problem you have is you're falling into the supremely retarded trap of taking the last thing you saw, and trying to extrapolate it to be a long term problem. The NFL rarely works that way, and its especially true with rookies. Thinking that Hamilton is a complete bust because he had a bad game (which I agree, he did) is the equivalent of suggesting that every good offense is going to score 40+ on us all year long, that we'll never improve, and that we'll get beat by literally every good team.
Again, real world rarely happens that way, and fans that think that way have an enormous track record of just being wrong.