The header shows that this is an averaged energy minimised NMR ensemble.
If you take widely differing structures and average them, you can easily end
up in the wrong conformational energy minimum, and if the energy minimiser does
not know about this problem (and why should it? Threonine with the Cγ and
Oγ swapped can be obtained commercially, after all) it will happily minimise
it to the swapped position.