Love the "disagree and commit" part. Perfectly encapsulates the situation where "I'm convinced this is a bad idea, but I'm going to trust you and support you."
It is a very top down hierarchal type of company, and engineers usually have little influence in general, and often are kept in dark on key decisions. Disagreeing in general is seen as a nuisance. A lot of it would disappear if managers gave concrete details on why a decision was made, but it usually takes a skilled manager to do that, and Amazon, as a large company, has a combination of good managers and plenty of not-so good ones.
I actually can't see it as anything other than a (potential) "I-told-you-so." Why are you specifically highlighting that you disagree, if you are then giving the go-ahead? You are the boss. If you approve something, ultimately it's your responsibility.
If you really trusted the person you would give them full authority on the decision without dropping your own agreement or disagreement into the mix.
Much more commonly it's applied in the context of group decision making. Imagine Alice presents design Alpha for implementing a sprint story. Bob asks some pertinent questions, outlines an alternative, Bravo, and explains his reasoning. A round of discussion with Carol and Dan commences. Whether the group decides on Alph or Bravo doesnt really matter. Everyone has had the opportunity to ask, and answer, relevant questions. Everyone (hopefully) has greater context and understanding of the context, risks, and intended outcome. Everyone, including both Alice and Bob, is expected to stick with the decision and move forward with that single implementation.
When IC's play "I told you so" theyre poisoning team morale and disincentivizing others from speaking up. When managers resort to "just do it" they're fundamentally failing to communicate context the team lacks, or failing to understand the knowledge they're missing. Neither is an acceptable pattern.
PS: six years at amazon as an IC
It was never a situation where he wanted to hold it over me, rather it was something that should give you pause and cause you to consider if you are really correct. It also gave me a lot of respect for the manager - that he would trust me even though he was convinced it wouldn't work.
In the end it was a success - but had it failed I don't think it would have been held over me. If you don't ever experiment you'll die as an organization.
Like this:
A: Hey B, could you look into problem P since you are the expert on this?
B: Sure, I think that we should do X.
A: Are you sure, I would go with Y.
B: I have considered Y and I think it is worse.
A: Then go ahead, you know this better than me.
Alternatively:
A: Hey B, could you look into problem P since you are the expert on this?
B: Sure, I think that we should do X.
A: Are you sure, I would go with Y.
B: I hadn't considered Y, thanks for bringing it up!
A: No problem, glad I could help.
You don't have to win or draw out every argument, and you don't have to be convinced of everything. Sometimes you just put a pin in it and go.