Not sure what the heck happen to my gourami?

Ok, so I decided to siphon my 29 gallon aquarium today which holds 22 fish well now 21....(8 neon tetras, 1 molly(had two but1 died two days ago)8 guppies, 2 Honey sunset Gouramis well one now, and 2 ramirez) I'm almost postive I didn't siphon him because I checked the bucket every single time before flushing it and too I counted all the fish when I was done and Another thing I noticed was that my filter suction cap fell off but I checked that too....Stressing out about what happen to my poor fish...I checked all over the floor...I could of dropped him out and maybe one of the dogs ate him but then again, doubt it cus I was watching them closely so that they won't get the ant baits we have around...Any thoughts of what might of happen?