I agree, the sat phone may or may not have been helpful, but leaving a group member behind to fend for himself, even if he was a guide, doesn't seem like a good idea.

In a reported incident in Arthur's Pass in NZ a few years ago, a small group left one of them behind to fend for herself, then reported her missing. Granted, this person wasn't a guide, but even more reason not to leave someone alone.

Btw, February is summer down there, so the temps wouldn't have been that bad but AP is known for wild weather , which I have seen firsthand and no place for an inexperienced hiker on their own.

Here is the SAR report posted on the AP website-

An inexperienced female tramper "abandoned" by her tramping companions in the Harper River became lost in the Long Creek area. Her companions reported her lost to Arthur's Pass Police late Monday(28-02) evening. A team consisting of Arthur's Pass Rescue and Arthur's Pass Police commenced a foot search of the Lagoon Saddle track at first light discovering the lost tramper in Lagoon Saddle hut. Her condition was that of dehydration because her companions had told her that ALL NZ water needed boiling before consumption, and they had been carrying all the cooking equipment when they abandoned her. We recommended she find new friends!

ps. their belief about boiling the water is totally untrue.