20 miles from 5000 feet.
That is 105600 ft / 5000 ft, or a glide ratio of 21.12 to 1. That's a little difficult to believe.
I think the LEZ has a published glide ratio of 13 to 1, but I still assume 10 to 1 in an actual engine out condition. He must have had a good tailwind or maybe some thermal activity?

Is this something that happened long ago or recently?