Raining fire from the sky doesnt mean it could not have come from somewhere on earth. An eyewitness account would not be lying that they saw it rain down from the sky, but not see where it came from.
Not a big deal, just a discussion more than anything.
If it gives you a buzz to make a scripture passage say something other than its clearly intended meaning; knock yerself out.
If fire had erupted from the earth, up into the air, and rained down upon the ground, the scripture would have said it that way. God is not the author of confusion.