I'm not a lawyer, so grain of salt, but I'd imagine the courts would still view those purchases to have been made by Apple since they would be for the benefit of Apple, not the hypothetical Apple Europe.

think of it this way: a US company is caught doing business with a company wholly owned by a sanctioned individual. say the us company argued "we weren't doing business with Pavel Sanctionovich, we were doing business with Pavel S. Inc., a UK company that just happens to be owned by Pavel.", would the courts accept that?