This discussion may contain spoilers!
It's silly, I know, and I'm not one of the biggest Luke fans around but I somehow questioned his death scene. Don't get me wrong, it was extremely well written and just wow but... 1) how was the walker swimming? I didn't honestly expect them to do more than... you know, being stuck in the bottom, not with all the decomposing tissues that should weight a lot if it was stuck underwater (like the zombie in the well in the Tv series) 2) Shouldn't be too cold in the lake for a zombie to move around? 3) Why in the name of heck Luke didn't even try to fight back? It's pretty much like he just accepted his fate...
Anyway, one of the best deaths in the whole Clementine Arc for me. And- I do apologize if my english is far from perfection but it's not my first language.