How do I say "He already went to do X for me", implying he is still in the process of X, not finished?


The other day at some festival a few japanese friends asked me something to
the effect of

アイスを買ってくるけど、行く？

But I had already asked a friend, who had not yet returned, to get some for
me. So I said

ジェームズがもう買って来てくれたので大丈夫。

What I intended to say in English was "No thanks, James already went to get me
some." But it seems that the japanese version of that statement could have
multiple meanings.

How do I differentiate between "He already bought it for me (and has completed
this process)" and "He has already gone to buy it for me (and has not yet
completed this action)"?

(もう買ってきてくれている could be a possibility, but for some reason doesn't sound
correct to me. )




ジェームズがもう買って来てくれたので大丈夫/もう買ってきてくれている would mean "James already bought it for me
(and now I have it)". I'd say

> ジェームズが(今)買いに行ってくれてるから大丈夫

or

> (今)ジェームズが買いに行ってるから大丈夫。

