That is not so much an assumption as a conclusion, backed up by research:
https://urban.uw.edu/news/crows-hold-grudges-against-individ...
https://crowlingo.org/journal/marzluff-mask-experiments-expl...
https://urban.uw.edu/news/crows-hold-grudges-against-individ...
https://crowlingo.org/journal/marzluff-mask-experiments-expl...