The fact that he was a foreigner provides a hint. It seems there's a general fear in the US of foreign workers taking the jobs of citizens. I wonder, is it not possible to switch employers when you have a work visa?
Comments from our idiot president and his ilk aside, there is not. I'm willing to entertain discussions to the contrary, but this is far from my experience either here in the Midwest, or on the East Coast where I previously worked.
You seem to have jumped to a conclusion rather quickly. Even assuming for a second that the hysteria was because the new function that GP wrote is complex, wouldn't the reaction to that would've been "Can you write it more clearly?" instead of the hysteria and pariah ceremony?
You version is quite paranoid on itself - junior denied learning and shunned for a single mistake.
For example. We have a redux based content editor that is quite slow. It is however more than performant enough for the use case. I would love it if someone refactored it though...