@Checkmate...how am I deluding myself when Tess herself actually said that she was doing that to redeem herself? The character actually said that to Lex, and he had an understanding expression on his face. There was more to that scene than just the mind wipe. Okay...I'll conceed that the scene wasn't "more to do" that was the wrong phrase of words to use. Lex's mind wipe was the sole focus of the scene but it was also to conclude Tess's arc.
I do stand corrected, the scene did have two purposes. One to wipe Lex's memory, two to get rid of Tess for the same reason they wiped Lex's memory.
The "omg, I'm doing this to redeem myself!" malarkey was just the window dressing. She could have said anything at all during that scene and it wouldn't have changed a bit. Lex's memory is gone, Tess is out of the story. Fini. Move on the next to-do list item.