There are a few ways of looking at that episode:
1) Roger is a character in a storyline directed by Angel, and attempts to "escape" into another storyline.
2) Ep. 14 represents the real condition of Roger Smith, and the other stuff is his fantasy/hallucinations.
3) Ep. 14 represents the beginning of the degradation/corruption of data in continuous cycling simulation program designed to keep the legacy of humanity alive after a serious your-arse-here type cataclysm. (note Ep.25 dialogue between Gordon Rosewater and Angel/Roger/Vera ... also note the condition of Gordon at the time).
4) A confused clash of storylines compiled by "Angel" who doesn't deal well with life outside her "holodeck" fantasy. (note the dialogue between "Roger" and "Angel" near the end of Ep 26).
5) Similar to #3 and #4, but from the perspective of "Angel" being the person who caused the annihilation, and her tried to recreate the world she destroyed by some action.
6) I can't remember the exact name of the "theory," but the idea that infinite alternate universes exist.
7) The idea that maybe time isn't as straightforward and linear as was thought.
Try reading parts of the Leviathan. Just might get some insight into the storyline I think.
Imagination and memory are but one thing, which for diverse considerations hath diverse names -T. Hobbes (Leviathan)