Might be outdated, since he talks about clotting generally but the agency in charge of halting the vaccinations mentions a specific rare complication today [1]:
> accumulation of a special form of very rare cerebral vein thrombosis (sinus vein thrombosis) in connection with a deficiency of blood platelets (thrombocytopenia) and bleeding in temporal proximity to vaccinations with the COVID-19 vaccine AstraZeneca.
Perhaps really just a bad batch somehow if this particular complication wasn't observed in the UK.
[1] https://www.pei.de/EN/newsroom/hp-news/2021/210315-pei-infor...