That has to be one of the lonnggggest fights in cinema history but I always wondered why they didn't just have the duel, have Ben eventually win, then have him leave, believing Anakin was 100% dead (even though he wasn't.)
GL was constantly saying "the movies are for kids" (esp the PT) and yet that scene resembles the brutal fight at the end of "The Northman." (also in a volcano)
And ends with Ben watching Anakin slowly get burned alive and then walking away with Aankin screaming in the background. My initial reaction was - "not my Ben Kenobi."
Also "I left him for dead" doesn't quite equate to "I believed he was dead and I'm shocked he's still alive" Like if Ben saw Anakin die - or what he believed was his death - then it would have been clearer.
As it is, even though Anakin is clearly badly burnt, he's most certainly not dead as Ben leaves, especially given Anakin is not exactly a "normal person" in terms of superhuman powers to help him survive.