For the record, I think picking Lazenby based on a fight scene (if that old story is true) was a dumb move, especially when casting for one of the most dramatically demanding films in the series, and one where proper casting might have made the difference between a new lease on life for the series and its premature end. We're lucky he worked out as well as he did, but really, saying, "He can throw a punch, let's make him the star" was a stupid move and sends a bad message about how seriously the producers took their own product. It does, however, demonstrate how completely Connery had redefined the role even by 1969, making Fleming's Bond into a rough-and-tumble superman.
And while I'm venting, I also never understood why Lazenby's fight test was interpreted as having gone well, given that he supposedly broke the stunt man's nose. Technically, I should have thought that would be considered a FAILED test.
First of all they had been testing him for months up to that point. Straight dialog, romantic scenes (with Australian and European actresses plus Diana Rigg), running, jumping, horse back riding, swimming (all filmed at Saltzman's estate). (See
my book for pics of these rare tests.)
When they got to the fight tests, George Leech paired Lazenby with a wrestler with as little screen fighting experience as Lazenby had - Yuri Borienko.
And for the record, Borienko was the first to land a real punch (not a precious swing and miss) - and he hit so hard that Lazenby said his teeth rattled. So Lazenby floored him.
Director Peter Hunt said the fight was so spectacular that if he could, he would have used it in the film. It obviously convinced the United Artists execs as well.
So yes, if Eon simply felt "He did one great fight test - so we hired him" that would be ridiculous. But my understanding, based on a lot of research and conversations with Hunt, Lazenby, Leech, etc. is that the fight was the icing on the cake, and while it did swing many people in favor of Lazenby, it was hardly the sole reason they hired him.
And while I see your point that a stunt injury is technically a failure, for a multi-million dollar film involving a lot of fight scenes - going with the more physically capable actor makes a lot more sense than choosing an "artiste" who pulls his punches. Isn't a bruise here or there, or broken nose even, worth the cost for more screen realism?