That's what I thought too.

I think it's the Abed timeline(the one where he get the pizza) because in the previous episode, Shirley is the one who told the group that Britta is using her marijuana lighter, Abed picked up a nickel and Pierce actually told them he banged Eartha Kitt.

Since you are bringing up the episode "Art of Discourse", I thought Britta is supposed to have an Ipod in like 2013 or something?

Also the scene with Lily delivering her baby, I think Marshall is with Barney for his bachelor party. That's why there are in a casino.

Am I the only one who noticed that Ted has yet to have a scene with Nora? Have he met her? And I think this was the first episode that Marshall and Lily saw Nora.