Review too short and vague to be useful
Unfortunately, when submitting to a conference, you don't have control over the process to the detail you are talking about. It will probably be the case that the useless review does indeed get less weight during discussions (unless the reviewer happens to be one of those reviewers who holds a lot of sway and can get a paper rejected with a vague and general review!).

I would urge against sending an email to the conference chair / organizers -- unless you are extremely tactful, any attempt to sway them with this method will come off as whiny and will only hurt your case (or, rather, your friend's case).

The best option is to write a rebuttal as you normally would: fix all the critical comments from the other reviewers, address each comment specifically in your rebuttal response, and thank the reviewers for their consideration. The good news is that you got one positive review.  While this is not normally sufficient for a paper acceptance at a very competitive CS conference, you have the chance to improve the paper as much as you can, and send in your rebuttal, and you should make the most of that opportunity.