I think I agree more with the parent than with you, particularly in engineering.

Lying in engineering means saying anything that's not true with any certainty. I wouldn't hold it against someone, but I would ask them to think carefully before speaking, to make sure what they said is true, as it can lead meetings to decide the wrong actions if nobody present happens to be able to contradict it.

Outside of engineering, all the same outcomes can occur, but proving the truth is much more difficult. And thus, while it may still technically be lying, it is impossible to tell and unfair to call someone on it.