Is addressing a man as ‘ingegnere’ regardless of his profession a thing? (Silly question, I know.)

I’ve come across this in two Italian films. Both cases can be explained by plot reasons, but there’s still some room for doubt, I suppose.

In Dellamorte Dellamore, an old lady calls the main character an engineer, and he always protests that he isn’t one. Plot reasons for this happening could be a) the old lady going senile, b) fragments of the main character's real identity resurfacing in his subconscious.

In Otto e mezzo, a hotel manager addresses the main character as engineer. Possible plot reasons: the main character didn’t want to disclose his actual profession to the hotel staff and introduced himself as an engineer off-screen.

I don't speak a lick of Italian. Sorry for everything!