Again I hit this question in a REVIEW lesson and made the same "mistake." I honestly see no difference in meaning in English if you say "Raj was swimming in Delhi yesterday" or "Raj was swimming yesterday in Delhi". The same information is conveyed. I am language-sensitive enough to see that there is a very slight connotative difference and a difference in sound, but the overall meaning of the two sentences is the same. The same information is conveyed. As such, both versions should be accepted, in my opinion. Please set me straight, if I have missed something.
Do believe me, you have missed nothing at all. (This is coming from a native Hindi speaker.) I would say that in fact there isn't even a slight difference in connotation, or stress, between the sentence in Hindi and your translation. Any such desired difference would be conveyed in speech by stressing the appropriate word (RAJ was swimming.../ ...was swimming in DELHI yesterday.../...was swimming in Delhi YESTERDAY...). In general it is true that languages which are very flexible in the order of words allowed -- like Hindi -- do usually have the different word orders convey slight shades of difference in meaning. In this instance, however, I would say your translation is completely and exactly correct, just as the provided one is.
Long story short: you are absolutely right, so do report this if you haven't.