The advantage of leaving Sulkowicz (Mattress Girl) off the lawsuit.

The Other McCain explains the advantage of Nungesser not including Sulkowicz in his suit against Columbia in Emma Sulkowicz Is a Vindictive, Dishonest and Crazy Slut — Allegedly

Now, if we ponder every possible avenue by which Paul Nungesser could (a) vindicate his reputation, (b) possibly collect a large cash settlement, and (c) deliver a brutal payback to Sulkowicz for her effort to destroy him, I doubt he could have done better than what he has done: Instead of suing Sulkowicz, he sues Columbia. Why?

1. Columbia’s endowment is reported at $9.2 billion — that’s billion with a “b” — which means they may (and probably should) decide that quietly paying Nungesser a couple of million bucks is a small price to pay for ridding themselves of this bad publicity.
2. Suing Columbia calls attention to how the university violated its own policy by permitting Sulkowicz to breach the confidentially requirements of the university’s sexual misconduct hearing process and, indeed, by endorsing this breach through Professor Kessler’s role in Sulkowicz’s “performance art” project.
3. Most of all, by not naming Sulkowicz as a defendant, this means that Sulkowicz does not have cause to respond to the allegations he makes against her in the Columbia lawsuit, and guess what? You can’t be sued for defamation because of allegations made in a lawsuit.

I claim no legal insight here, but this sounds like a very clever strategy.  See McCain’s full post for more.