A fun aside is the pastor of our church loves to use the scientific method to get deeper understanding of the New Testament. Some of the things he has come up with... wow. His sermons are great for engineers and scientists! (He was a engineer by trade before his calling).
Sometimes, like in the case of the fire birds, it will be a very long time before answers are scientifically tested due to the complexity and difficulty of testing in a controlled manner. I cannot imagine how well that would go for researchers if they started a wildfire to get solid recorded evidence, and in the process created a catastrophe.
For fish and fire transport with birds, I would suspect that a single recording of the event still would not be enough for most scientists. It would have to be many documented events in different settings before it became accepted, and this may be impossible due to the infrequency of these events.
Like any good investigation, if you ask several different people who have no relationship to each other a set of questions that result in the same answer, you have a fairly good shot at having reasonable source events. Perhaps they are all wrong, but the chances of incorrectness diminish with a greater sample set.
We know how well this multiple observation goes with alien abductions... so I guess we will never know for sure and rack all this up with wive's tales.
