This particular case happened well over a week after vaccination.
Clots only cause strokes if they arise or lodge in the brain. They can occur anywhere and they can also move, if a venous one and it breaks off they can lodge in the lung and become a PE.
In our family we have a known blood clotting disorder discovered first with me but now, I look at my mother and grandmother and they too had signs of minor strokes long before they had their major one but that was many years ago. My niece who inherited this condition also, and in her thirties was on aspirin as she had markers in her blood that were being watched, and was on preventive aspirin. She developed a DVT in her pelvis, and she like me, is now on anticoagulants. We have both had AZ vaccine.