We didn't adjust for native vs. non-native speakers. Despite that, we did end up hiring several people from outside the U.S.
In general, I think native and non-native speakers should be held to the same communication bar. No one is demanding perfection, but it's important to be able to get ideas across without noise. Moreover, and I think some commenters mentioned this below, a resume isn't written on the fly. Ideally, someone should be self-aware enough to know that grammar/spelling isn't their strong suit, whether they're a native speaker or not, and that should inform whether they opt to have it proofread.
In general, I think native and non-native speakers should be held to the same communication bar. No one is demanding perfection, but it's important to be able to get ideas across without noise. Moreover, and I think some commenters mentioned this below, a resume isn't written on the fly. Ideally, someone should be self-aware enough to know that grammar/spelling isn't their strong suit, whether they're a native speaker or not, and that should inform whether they opt to have it proofread.