Perhaps, but they were still under the impression that it might have been someone with a lit cigarette — which also leads me to believe that it may have been a person. If they can't determine within a few hours whether it was a gas line or a cigarette?
She has the ability to make you see things. Several of us were affected to the point that Bruce changed into the Hulk because of it. Not the same thing, obviously, but I'm not discounting it.