First off, my belief is, that understanding what can happen won't change what you do. You need to stick with your plan, and then if something goes haywire, follow the plan and most importantly don't beat yourself up over it.
I realize what I'm about to explain is obvious to most ET'ers, I'm just not a real clever guy, so this was new to me.
The really basic example is where a familiar face on the floor starts bidding up the contract and gets everyone else excited, but the famiiliar face has his cronies steadily selling in the electronic market.
As an aside, Borsellino pointed out that the price differential between open outcry and emini contracts (referring to the SP500) can be just enough to give his computerized systems conflicting signals.
Borsellino basically feels that to make for a truly level playing field you gotta get rid of the games.
I wish I could give you more specifics, but my mind was just overloaded with info that day, I walked away remembering more the concept than the specifics.