Revealing mistake: When Clarice is at the archive, she sees two articles, one entitled "Baltimore Psychiatrist Receives Highest Honor" and "New horrors in 'Cannibal Trial'." The column beneath both titles to the right is exactly the same, and in the first article, that same column is repeated at the leftmost and rightmost columns and in the second, is repeated at the rightmost column. That same column is scattered on every article she sees. (00:21:35)
Revealing mistake: During Lecter's escape, the SWAT team arrives and jumps out of the police car at the courthouse with their Ithaca 37 shotguns. All of them are shown chambering their rounds except the the officer on the right, who pulls back again on the fore stock and asks "ready?" That should've ejected a shell and left the gun unloaded. (01:21:40)
Revealing mistake: When Clarice goes to Crawford's office, on the board there is a newspaper article titled "Bill Attacks Again, Woman Missing..." on the left and another titled "FBI Links 'Skinning..." on the right. The three top paragraphs on the left columns of both are identical (with different spacing). Two of the yellow lines on the right one are the same too.
Revealing mistake: In the examination of the corpse at the funeral house, a bug is removed from the throat of the victim. The bug is lodged deeply into the throat of the girl, to the point that when they pull it out, air is released from the throat it obstructed. But if you look at the first shot when Agent Terry puts his tweezers in the girl's mouth, you can already spot by the molar the tip of the cocoon - the bug is not that big, if the agent had already pulled it by that much the gas release would have happened already. (00:45:15)
Revealing mistake: During the autopsy at the funeral house, Agent Ray Terry is taking pictures, aided by the funeral home assistant, Lamar. The actress playing the dead body does a great job throughout the scene, but exactly when it's time to take the first picture you can see her blink right as Lamar's hands pass over her eyes. (00:44:35)
Answer: The body in the bathtub is Mrs. Lippman, the previous owner of Jame Gumb's home. Notice the long grey hair coming from the scalp. He would have wanted someone young, large, and whole.