Bear in mind, also, that the lesson is mostly likely based on the original 1980 studio version of Living After Midnight. At that time, the band's guitarists were KK Downing and Glenn Tipton. Richie Faulkner was literally born in 1980. Therefore, the way he plays it live is possibly different from how it was played by the original guitarists in the studio in 1980.

Looking at it ,though, I guess the difference you're referring to is playing the A and B power chords at 5th and 7th position, rather than down at 2nd position the way Faulkner demonstrates? It's possible, of course, to play the exact same notes in either version, with only slight tonal differences that might not be noticed with a higher gain sound anyway.

I have found some teachers do make use of available videos to help cross reference how the original artist played various parts. This particular lesson, though, is one of the older ones here, having been published in 2009. That's only 4 years after YouTube launched, so there may not have been that much Judas Priest video uploaded to research at that point, anyway.