To me the real miracle was the peace and joy described by the pilgrims, which for most Christians, needs rekindling from time to time. If I felt that peace and joy, I wouldn't care much one way or the other about the external firey manifestations.
At the moment when he took a taper to give of the divine fire to all of those in the church who had torches, scarcely had he come out of the tomb, when he saw the church suddenly filled with a divine light. The faithful were standing on the right and the left, some near the door, some by Calvary, others near the cruciform chain suspended from the ceiling and all around which they had hung their lamps, the chain, that is, which passes for representing the center of the world and which is there as a sign, so that all men might be astonished at the apparition of the divine fire. Niketas, 947 A.D.
The same source also tells that a governor brought a copper wire instead of a wick, in order that it won't ignite and the whole thing would fail to occur. But as the fire descended, the copper burned. The descent of this fire from above on a day, which recurs after a specified time span, gives us occasion to be astounded..Muslim historian al-Biruni, 1000 A.D.
The the 11th century Christian writer Abelfaragius quoted a Muslim detractor of the Easter Eve ritual
. . . When the Christians assembled in their Temple at Jerusalem to celebrate Easter, the chaplains of the Church, making use of a pious fraud, greased the chain of iron that held the lamp over the Tomb with oil of balsam; and . . . when the Arab officer sealed up the door which led to the Tomb, they applied a match, and the fire descended immediately to the wick of the lamp and lighted it. Then the worshipers burst into tears and cried out Kyrie Eleison, supposing it was fire which fell from heaven upon the Tomb; and they were strengthened in their faith.
Somehow I think the Greeks can make an electrostatic discharge happen (and did so before the science of electricity was known) that lights the lamps through ritual that is not deceptive but can be explained through sceince. The blue fire that does not burn is "ball lightning", IMHO.
“I had heard about the Holy Fire and was, when I made my trip to Jerusalem for Pascha, not disbelieving. I found the idea that such a phenomenon existed interesting, and I wanted to see it for myself. What I saw was interesting. ...The Church was crowded beyond description. Before the manifestation of the Holy Fire, the Arabs created a tremendous scene, proclaiming the correctness of their Faith and running here and there through the Church.... Then the Holy Fire was brought out by the Patriarch. During this time, I could see what appeared to be flashes of blue-colored light bouncing off the walls of the dome of the Church and through the galleries. There was an electric quality to the air, almost like static electricity.”
Dr. Eugene Zavarin
Professor of Chemistry (Retired)
Wood Products Laboratory
University of California, Berkeley