shift blame(Ah, well, I don't want to shift blame, but yeah, it was... yes, you're right when you assume that Sammi had something to do with this.Taras)
pass the buck; pass the buck(на кого-либо • Your team member denies any negative criticisms you are making and passes the buck onto some other colleague.)
throw under the bus(He didn't do his job properly, but instead of admitting it he threw his colleague under the bus – Он не выполнил свою работу как следует, но, вместо того, чтобы это признать, он возложил всю вину на своего коллегуTaras); throw someone under the bus(Taras)