I think what you're hearing may be the melody jumping to and/or away from chord extensions, which makes them stand out more than if they were approached/left by step. The harmony for the section from 1:29 to 1:43 is:
Eb M7(9, or arguably an anticipation of the next chord), Bb M7(9), D mi, A mi7/C(b13) [or C add13(11)]
with the extended melody notes listed in parentheses. In particular, the F to C to F jump happens twice (1:31 and 1:39) and doesn't completely sit within the unextended harmony either time.
EDIT: Not sure how familiar you are with theory regarding chord extensions and their notation, so if you have questions, certainly ask.