Factual error: During the scene when Megan and the FBI are making the house entry, a scene cuts to two FBI agents, one with a M4 and another with a MP5. The agent with the MP5 has the magazine in his weapon installed backwards. (00:05:10)
Other mistake: The MP5 carried by one of the Federal officers breaching the meth lab has the magazine facing backwards.
Answer: It takes 24-48 hours before a decaying body begins producing a decaying odor. It takes a number of days for it to intensify enough to be immediately noticeable when walking into a room.
raywest ★