In case anyone is confused, ‘hairpin’ refers to the graphic representation of crescendo.
I am seeing in a score, a solo cello part has ‘cresc.’ but the individual part has the hairpin. These are two different things, in the sense that ‘cresc.’ generally means to do so until the next written dynamic; whereas the hairpin is only for the specific duration of the graphic. These are not interchangeable and should not change from score to part.
Ditto for ‘dim’ and the reverse-hairpin.