Disclaimer: Work culture has changed since 2009 and obviously none of this applies if you work with/for someone who can't take any criticism or disagreement and expects subordination.

I think the issue is not disagreeing with one's boss, but what relationship you have with your boss.

There's a big difference between hostility and wanting to win against the other person vs. trying to find the best possible solution for the team, and clashing on what that should look like.

Some of this is about communication (continually centering on what goal one is trying to reach and validating the other party's perspective) other stuff is basic manners (don't make a public spectacle of your disagreements, especially in front of your boss's boss), but much of it boils down to relationship skills.

I think more people in tech should understand basic relationship skills and how they apply at work. Work is more transactional than a friendship or a marriage, but the core parts still matter: everyone wants to feel seen and heard, not invalidated and attacked.