I can't speak for others, but it does not conclusively convince me. It looks bad, and I dread that it's true, but it is not conclusive evidence IMO. There is a reason it is categorized the way it is. It, alone, is not even probable cause. It's "reasonable suspicion" in a court of law.
Cadaver dogs CAN hit on blood. My child had a head injury, it bled a lot, and I took her to the hospital. 8 hours later we were home and I cleaned it up. The decomposing blood WOULD cause most cadaver dogs to hit on that spot of my house.
The fact that a cadaver dog would most likely hit in my house leaves me to want more evidence.
But I will absolutely confess that my heart sank when I read that. Which means I do fear it to be exactly what it appears to be.