Most of the time, the non-native speakers learn English from the books instead of absorbing the local dialects/nuances since they don't hear people around them speaking English. However, depending on the quality of books / teachers, this means they pick-up a weird/artificial view of English (speaking is still difficult because you don't get to do it everyday - this is changing though). Then when one lands a job requiring English communication, they pick-up the "do the needful" type of oddities by observation/convention. So when they communicate with a native speaker, what comes across is a unique edition.

Interestingly, I can speak four languages (three fluently and one semi-fluently) and there is no equivalent of "do the needful" that is actually used in any of them - you just specify what is required - the closest non-specific equivalent I can think of is "take a look at it"/"take care of it"/"resolve it". God knows where that came from.