Other mistake: Season 04, Episode 14: In the scene where Lynette and Tom are fighting about Lynette having taken Kayla to see a therapist, and Kayla walks away, you can hear Tom yelling about Lynette having a distorted reality and that she can't pull crap like that. In the scene where Kayla comes back into the house after conning the twins into jumping off the roof, Tom and Lynette repeat the same dialogue again.
Other mistake: In season 3 it's revealed that Mike Delfino's doctor at the hospital is Ida Greenberg's nephew. When Ida dies in season 4 her only distant relatives come from another state, and there's no trace of her nephew from Fairview.
Other mistake: Season 5, episode 20, "Rose's Turn": Carlos carries Lynette to bed when she passes out after falling in the shower. She was obviously very wet all over when it happened, and is still wet afterward, however, his suit is completely dry.
Answer: He was investigating the lead not the case.