Well really if you wanna dumb it down its either man on man blocking or slide protection where you move to and block everything that shows up on the side you are sliding to.

If you wanna make it a litte more complex you have all sorts of mixes of the two. When you start involving RBs and chip blocks, passing defenders down the line, cross blocking in pass pro and such, well then it gets hard pretty quick

I used to run the "3 jet" protection, we called it ABC because those were the gaps we slid to with a Larry or Ringo tag to know what side to slid to. We had man blocking on the backside, just like the Saints, if they had a 6th rusher the RB would have to pick him up, working to the backside or the QB could send the RB on a route and be responsible for that passrusher himself.
At times it will happen during games that the QB (or C, depending who makes the protection calls) will call a protection going the wrong way just because you get caught up in it all, I would not be surprised if that was what happened here and that stuff will get cleaned up. Usually you enable the other O-line players to make a correcting call if a bad one is made, or if they see a potential blitzer creeping towards the LOS that the QB or center havn't seen.