Seconded this summer by Mark Jenkins, Jon Krakauer outdistanced G. Weston de Walt in assessing survivor’s guilt and blame games in the May 1996 Everest disaster. Walter Bonatti had assessed 1954 on K2 (second of the remote Kashmir Pakistan Karakorams), while Peter Zuckerman, Gerard “Ger”/”Gerry” McDonnell’s brother-in-law Damien O’Brien, Marco Confortola, Wilco van Rooijen, Ed Viesturs and Graham Bowley have written their versions of the August 2008 catastrophe on that latter peak, now cobbled into The Summit.

For authenticity on the reconstructions near Switzerland’s Eiger that form a lion’s share of the film, director-producer Nick Ryan relied on climbers, Sherpas and other support people physically present at the event (with the telling non-cooperation of the Korean team leader). Mixing scripted material with archival and aerial shots, stills and movies taken during the assault, voice records, after-the-fact interviews plus others videoed by the central subject’s family, he fleshes out the hour and two-thirds.

The result is homage to thirty-seven-year-old McDonnell and the ten others who perished (in addition to three seriously hurt and/or frostbitten) in that worst day on the world’s second highest but first most dangerous mountain, from whose top more than one in four does not descend alive. As in the more publicized Nepal fiasco, what happened here, and why, remains controversial, innocence and guilt, heroism and cowardice doled out depending on the teller. What emerges from the claims, counterclaims and disclaimers is that, while faulty judgment in the face of simple bad luck played a not inconsiderable rôle, other factors came into play.

In the background are indications, even accusations, of inexperience, overcrowding, hubris, vainglory, greed and condescending misuse of local guides and porters, This, and by implication, condemnation of the commercialization of the once romantic, gentlemanly amateur, sometimes solitary sport of mountaineering.

Disaster struck on a day described as perfect, a once-in-a-century weather window. On the ascent a Serbian climber fell to his death, followed by another fatal accident to a member of the French team, as others, including the Americans, turned back because a late start had not allowed enough time. Two dozen, however, continued on from final Camp IV despite mishaps like an ill-considered placement of safety ropes and the always-present threat of avalanche from an enormous overhang ice-ridge serac above the Bottleneck rock gully.

Nearly stereotypical in his bonhomie, tales and songs, Alaska-based Ger became that day the first Irishman to scale K2 aka Godwin-Austen. Alongside was Nepali friend Pemba Gyalje Sherpa, equally a professional mountaineer rather than a porter, who brought down with him Ger’s satellite phone and camera.

Numbers among those who sought the summit and those who remained at lesser heights as backup or comprised the following day’s rescue mission, film-recorded what they experienced and, often for a price, made the footage available.

In the resulting assemblage of materials and sources, it is not always clear what is what, when and from where, nor, though speakers are identified on first appearance, is it certain who it is offering whatever opinion. Which screen person is an actor, which real? Like many other current cluttered non-fiction films, and indeed like the trophy-seeker-overburdened 8,000-meter peaks themselves, The Summit would have been better for pruning. A sharpening starkness would have served the mountain’s and its story’s majesty, even if “we had an incredible amount of material, and many strands and stories which we could use.”

Darkness trapped eight climbers on a face in the mythic “death zone,” a couple bloodied and agonizingly visible from below in early-light zoom. Bodies were left there, frozen solid for ever, or brought down or, in Ger’s case, never found. His loved ones are the end focus and last word, as, believing he sacrificed himself -- “That’s how he was” -- they seek to unravel reasons and truth.

(Released by IFC Films and rated “R” by MPAA.)