"as if + … + were" v "as if + … + was"

"Journalists talked about “the profile of a serial killer” as if it was an a priori blueprint that offered a checklist for a type of offender rather than being the analysis of behavior specific to a crime scene (or set of scenes)."
More: Are you Profiling, Profiling, or Profiling? | Psychology Today

I checked up the Free Dictionary in which I noticed that as if followed by were while in the given context as if being followed by was. Questions: Does this mean that what has been mentioned in dictionary is formal? Does this mean that in American English (as if + he, she, it) can be followed by was when we want to describe an unreal situation?

I can't speak for American English, but one very rarely sees "were" used in this way in British English any more. The guidance used to be that one used "were" for the present and future, and "was" for the past. For example, "If I were a rich man..." and "My head felt as if it was bursting". However, most British people use "was" in both situations now.