Factual error: It is the weekend and Valentine's Day. We see in the following episode that it's 2006 and their calendar matches the real one, but Valentine's Day was on Tuesday that year.
Desperate Housewives (2004)
1 factual error in Thank You So Much
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?
Bree Van De Kamp: It's the age-old question, isn't it? How much do we really want to know about our neighbours?
Trivia: Teri Hatcher (Susan), Felicity Huffman (Lynette) and Eva Longoria (Gabrielle) are the only cast members to appear in every single episode of the series.
More questions & answers from Desperate Housewives
Answer: He was investigating the lead not the case.