Maybe they had it before they were vaccinated. Or perhaps they contracted it right after they were vaccinated since the immunity takes time to develop.
In any case my understanding is they were most mild or no symptom cases with 2 requiring hospitalization.
I don’t really care anyway since I won’t be getting this vaccine just as I have not had any flu vaccines, ever.
I got the flu vaccine once, never again, and I’m with you, I’m not getting the COVID vaccine.