It's really a balancing act. It's also surprisingly difficult as an eng-exec with a deep eng background to correct some things without accidentally undermining those around you. Happy to provide examples of this comment is too vague.
There’s definitely a balance and even within the challenging something that smells wrong, there are grades of undermining, ranging from public pronouncement of “y’all are lazy or incompetent and I know better” to private “I think I misled you about a core constraint and that may have led you to assume the scope needed to be 4x as large in order to address that perceived constraint.”
I find it extremely rare that a source of issue is the former and relatively common that I’ve been confusing or incomplete in my own guidance. If it’s in my head only, it doesn’t exist for my team and I need to fix the issue at the source (me) and, in so doing, that might change the engineering course and/or estimate.
(I have also accidentally undermined my team unrelated to the above; IMO, the best response there is to acknowledge it and try not to repeat it, because if you do, people in the company are prone to try to exploit that to drive outcomes that they think is best for the company. That’s fine, but it may undermine your ability to lead change in the company and cede it to others.)
