Love Is in the Air (a.k.a. What I Did for Love) - S1-E14
Factual error: Lynette's neighbor tells her that the pot Lynette's sons gave her is really hers, the neighbor's, and she bought it in Costa Rica. She turns the pot over to show Lynette that the price is marked on the bottom, with a number followed by the letter p. One supposes that the p might stand for peso, except that the currency of Costa Rica is the colon, which consists of 100 centavos. No p in sight.
Look Into Their Eyes and You See What They Know - S5-E19
Other mistake: In an earlier episode where Edie and Susan are driving Martha Huber's ashes to the lake to be spread, Edie gets a flat tire and Susan changes it. In this episode, all the girls are driving with Edie's ashes and they get a flat tire. Susan asks "Does anyone know how to change a flat tire?" Did she forget how?
Gabrielle: I feel a wave of morning sickness coming on, and I want to be standing on your mother's grave when it hits.
Trivia: Across Season 4: Two Lois Lanes appear together in this season: Teri Hatcher played Lois Lane in The Adventures of Lois and Clark and Dana Delaney voiced Lois Lane in Superman: The Animated Series and its follow-ups.
Answer: He was investigating the lead not the case.