If the truth is how you see it (as the tagline on the Cruel Summer poster teases) then it's up to fans to interpret whether Jeanette or Kate is telling the truth about what really happened in Kate's kidnapper's basement. Is Kate a liar, or did Jeanette really see Kate while she was being held captive and choose not to say anything in order to protect her newfound social status?
We don't know the truth yet, but Episode 3 of Cruel Summer hints that Jeanette may be much more manipulative than we realized. The third episode introduces a side of Jeanette that is totally sketchy — and though her sketchiness presents itself in different ways, it's clear that, throughout all three timelines, Jeanette is more than capable of lying to protect herself. If we didn't think Jeanette was capable of something as diabolical as what Kate accused her of, well — maybe we should start thinking that way.
Here are the moments from Episode 3 that should make us very suspicious of Jeanette...
Jeanette Steals Mallory's Weed
Jeanette and Vince are shook when Mallory invites them to smoke pot, which she stole from her mom. Despite having already broken into Martin's home, and done a slew of other dares from their master list, Jeanette and Vince both act completely uncomfortable with the fact that Mallory brought drugs into Jeanette's house. I say "act," because it's revealed later in the episode that it is, mostly, just that for Jeanette. She tells Mallory that she flushed the weed down the toilet in order to get rid of it, but in actuality, she has stolen some for herself — as we learn when she poses with a joint in the mirror, a sign of the "cool girl" who will emerge the following year. The fact that Jeanette was able to lie to Mallory — who was also concerned about getting in trouble with her mother if she didn't return at least some of the weed to the house — and even convince the audience she was being genuine makes it so that we really, really can't trust what Jeanette says and does.