Israel invades the gaza strip.

Actually, it doesn't even matter, for the sake of this discussion, what actually happened.
None of them could see the future. It's only logical to prefer to save your life than your property.
However, it's equally logical to realize that anything left behind would be seized by the enemy. Expecting your enemies to be murderers but not thieves is a bit absurd, don't you think?
They were "expecting to return" because they were expecting the Jews to eventually be defeated. That hasn't happened yet.

Oh good, now I can finally stop arguing here, and focus now on the damm flash mob in front of one of my university's buildings where there's pro-Israelis on one side and pro-Palestinians on the other.

I usually go on the side that is unrepresented (see: Palestinians here) but both sides were as equally large, so I had no idea. So...I walked back to my dorm where now I'm on Southperry. I might walk back, go in the middle, and yell some nonsense "Why the hell can't you guys just live peacefully together?" Or some crap like that.