"Earthquake light is an unusual luminous aerial phenomenon
that reportedly appears in the sky at or near areas of
tectonic stress, seismic activity, or volcanic eruptions."
Considering there were reports of seismic activity in the area around the approximate time of the event, it's possible that ionized air promoted formation of sprites and/or ball lightning.
While earthquake light does seem like one of the better explanations, the length of time it was observed (>30 min) would make it one of the longest observed earthquake light sightings.
Considering there were reports of seismic activity in the area around the approximate time of the event, it's possible that ionized air promoted formation of sprites and/or ball lightning.