Am I the only one puzzled by the backlash on using canines in Fire investigation;
the fact that certain quarters have misrepresented/misinterpreted their use,
does not make the canine a useful tool (portable hydrocarbon detectors are subject to misinterpretation too).

Two possibilities :
- the dog reacts positively - take a sample and have it analyzed;
consider other sources of contamination if results are positive for an accelerant.
- the dog doesn't react positively : clear some more debris, and work the dog again;
if no reaction, do not exclude an incendiary fire out of hand.

The daug is just another tool, saves your knees.

Just like all other circumstantial evidence, it must be tested - but ignore it at your peril.
If you can't distinguish between fact and indication, then don't do Fire Investigation.