As cabin crew, I witnessed a similar event in the cabin of a B757 many years ago. In rather turbulent conditions, a ball of lightning flew down the entire length of the aisle from front to back and seemed to exit via the R4 door. Pax were cr@pping themselves. An attractive young female asked if I would "hold her hand if we were going to crash," to which I reassuringly replied "sweetheart, if we we're going to crash you'd be holding my knob not my hand!"
On a separate flight, again on a B757, the left wing was struck by lightning during the latter stages of the descent. Sounded like the No.1 engine had exploded! Uneventful landing followed, without the Captain even making an explanatory PA to the rather concerned passengers.