Originally Posted by cosmo cramer
Touchdown point decides your landing distance, not threshold crossing height.
To a first approximation (no flare) that is correct (*). However, the flare will take the airplane above the glide path, and the touchdown point will be beyond the aiming point. How much depends on the length of the flare. For a given amount of "gee" in the flare arc, the length of the flare increases with the change of rate-of-descent (relative to the runway surface) between the start of the flare and touchdown, i.e. with the angle between the glide path and the runway.
The AFM landing distance is measured from "a point 50 ft above the landing surface" for standard temperature. It is corrected for altitude and wind, but not for runway slope so it is sufficiently conservative for uphill sloping runways to absorb some increase of the flare distance.
Therefore the pilot of the OP did nothing wrong, and the captain had no reason to reprimand him or to call for a go-around. But suppose the captain said something like: "Look here, your landing was good, but it would have been even better if you had managed to cross the threshold below 50 ft" - would you disagree with him?
For downhill sloping runways the AFM landing distance is unconservative. Would it be wrong to use a glide path angle of -4 degrees when approaching a runway with 1.7% downslope?
(*) You seem to refer to 'touchdown point' when you really mean 'aiming point', i.e. the rectangular runway markings at the intersection of the glide path and the runway.