I don't know maybe he should be assumed as a newbie for playing his card that way or maybe he just do that without knowing what could be the aftermath of his action,
I guess both of it still defines as being a noob on that game but even though Poker is known to be a game of skill and the player did some calculations, there will still be times that the result that they will get is different from what they are expecting, that is because this was still gambling and there are still risks that entails on it.
in gambling, everyone will be surfing on the opportunity he could be placed with as against his opponent, this is gambling, every of our moves should be taken with care and we must be deliberate about them in other for our opponent not to use any as against us, this was his mistake and i hope he will learn against the next time.
Like I said earlier, there are also skill-based gambling and not taking the opportunity does not always mean that we are a noob but it can be a part of the plan to gain more advantage later on. Also, gambling is not only about being serious and trying to secure a profit but it is also about relaxing and passing out the time. We don't know, maybe that guy is already rich, so it's not really a big deal for him losing such amount.