The patients receiving the Pfizer vaccine were older, sicker, and more likely to be in nursing homes. The RR fell to 1.15 for pulmonary embolism and 1.26 for immune thrombocytopenia after controlling for this. The baseline rates were on the order of 0.06% and 0.01%, respectively, so even assuming that this is a real effect and not just a result of inadequate controls, this is roughly equivalent to an increase in absolute risk of 0.01% for PE and 0.003% for IT (doing very rough math in my head).