It doesn’t make sense. The house is squeaky and has hardwood flooring. The intruder isn’t wearing night vision goggles nor have a flashlight. If it’s BK then he’s furthermore has visual snow. The footsteps rushing around and light toggling weren’t observed during the short time frame.

The pca lays out the timeline. It’s a short timeline that includes walking stealthily/slowly and murdering four adults in bed. I don’t think he would have the wherewithal to realize the sheath was gone then return to the house right after killing two women. Plus DM would have seen or heard him or X roaming about since she was investigating noises within the main thoroughfare for that exit and common area.