It's a way of leaving Watney behind that seems maybe plausible if you don't think about it. That's the best I can say about it.
That's not a lot to say, really. I prefer my sf to engage my braincell a bit more than that. Well, I'll probably see it at some point, but I can't say that I'm motivated to actually go out of my way (e.g., to a city with a cinema, or to log onto the wife's DVD library website to book it) for it. I'll see if the copy of the book turns up on the recreation room's library. Frequently the book is considerably better thought out than the screen play. Different audiences.
In Earth's atmosphere, it is possible for wind to drive solid objects through others, but it typically takes a tornado.
A rather different situation. In one case, one object is stationary and the other is acquiring kinetic energy by being blown around in the wind for an indeterminate period of time. (Actually, there was another SF film a few years ago where the MacGuffin was a device for measuring some aspects of that movement.) In the other case, both objects start at zero velocity (with respect to the ground and each other) in the significantly slower wind at ground level.
I have no idea what sort of wind would be required for the Martian air to do that.
I don't have numbers to hand, but work has been done on this looking at dust devils (mini-tornados) on Mars, imaged by the very mapping satellites I mentioned earlier. There are also weather stations on all of the landers, of varying degrees of complexity. We may not have as good an understanding on Mars as we do on Earth, but our scientists and their robots are finding out this sort of thing.
I swap tweets from time with a guy whose signature line was "There is a robot on Mars. I give it instructions, and it does what I tell it to do." I like keeping up to speed on interplanetary exploration activity.