It was ok. The concept is pretty good, could work if it was expanded.
Kinda cringed at the blatant coincidences (the moment she manages to say she loves him she gets shot, she got bit by a zombie when she was about to confess) but it's kinda to be expected from a oneshot.
@MrGoose Coincidences that start a story are fine, coincidences that end a story are horrible. Neither of the coincidences in this one-shot is the deciding factor in the ending so it's not bad writing.