I would not have guessed that any of these people were non-native speakers or didn’t grow up bilingual. They have an exaggerated way of speaking but without your context, I would have assumed that was because they were deliberately enunciating their words for a presentation/demonstration.
I was told once when I was learning a new language that I have a “tv” way of speaking because the only exposure I had to the language until then were courses where the instructor was speaking very clearly in a way that sounds unnatural in casual conversation :)
What for you are the giveaways that they are not native speakers?