In all likelihood, the engineer meant "that approach/idea/decision has risks we should consider." The VP likely heard "you are suggesting something wrong/dangerous/ignorant."

A nuance here is that the engineer probably implied that "(We should be) careful (in our consideration)" and the VP perceived "(You need to be) careful (and you don't seem to be)"

I'm possibly paraphrasing and simplifying too much but "How to Win Friends and influence People" mentions being very cautious about correcting people, more so correcting them publically, even when you are correct.

Such a good book, I'm about due for a re-read I think.

It also places the speaker in a position of authority, admonishing someone who is still learning. "Careful!" is what we say to children. A high-status person may be particularly sensitive to this, but nobody likes to be talked down to. As I alluded, I hear this amongst engineers and filter it out as verbal fluff, so there are cases where it is ok.

An easy alternative to "careful" is "I'm not sure about that" or even "I disagree." Both are what peers would say to each other. In scenarios where a high-status person is not receptive to being talked to as a peer, well, you get to add all the deference and qualification you need to, but it comes down to stating disagreement in a non-disagreeable way.