Continuity mistake: Right after Frank gets shot he shoots Portman and you see someone helping Frank get his jacket off as he's lying on the ground. The camera angle changes and you see his jacket back on and someone is starting to help him take it off again.
Continuity mistake: When Frank pursues the killer at the lake house, through the snow-clad forest, his breath doesn't show. But he comes from a warm house directly out into a freezing night air.






Answer: The fact that Frank hires an older gray haired bodyguard for Rachel after he quit tells me that he didn't want her getting involved with another man, because his intention was that he would be involved with her.
You should read the script; some of the deleted scenes mention the part where she slaps him and why, and the ending when she gets back off the plane. They talk and she gives him a cross.