Kassidy discerns nothing that could be construed as a physical trap. Nothing is moving, no objects are strewn about, and there seems to be nothing readily available to provide a hiding place for such devices. No cracks in the walls are wide enough to hide a detonator... the single rug on the floor of the hall is so threadbare, one couldn't possibly conceal a trapdoor under it, etc. The only sounds that can be heard in the night, is the faint buzz of city lighting, and the sound of someone driving lazily down the street.
Michael will easily notice from his entry behind Daniella, that the man he left drained on the kitchen floor has been moved. Or disposed of, whichever the case may be.