When did Damon have time to vacuum AFTER he realized Danielle was missing?
The uniformed officer responding from the 911 call was there when he returned from driving around the block, and did a walk through with them, and then kept the family outside until investigators arrived, who were then in control of the premises till 10 p.m. or so. And they spent the night at the neighbors, because of the mess left by evidence technicians.
The vacuum thing is a red herring tossed out by Feldman.
Investigators took two vacuum bags, one from the trash, one from the machine itself. Brenda testified she vacummed the downstairs (sometime before Danielle was missing), changed the bag and took the machine upstairs because she intended to use it upstairs that wknd. Events intervened.
The investigators also took the entire steam machine into evidence. If they had found evidence of blood in either, they would have been on those parents like flies on cowpats.