Spoiler, not blanking out the whole body, but how did they jump to these conclusions?

In DOD, how did they immediately jump to the conclusion that Caleb was Rosalind’s protégé? As if in a city like LA there could be only one person who could possibly kidnap Lucy?

Then in season 6, Tim immediately jumps to “the shrink is a mole” based off that cryptic conversation with Mad Dog before he jumps off the building? All he said was “She knows all my secrets.” That could literally be anyone. I think season 6 might be explained because the season was a bit rushed due to the various strikes.