I don't think I'd consider that a mistake. Not that it matters to everyone but it's one more asshole thing to know Trump did, which was only publicized because Zelenskyy respectfully asked for his turn to speak. Other leaders are likely to have taken note of that: Trump isn't even pretending that you're equals.
To some common folk, it will make Zelenskyy look weak but also consider this exact thread in which people say his calm demeanor makes him look strong. I'd wager Zelenskyy is interested in impressing the latter folk and not interested in impressing the former.