"It's not a political decision"
It likely is, though.
From the perspective of the regulators, there are asymmetric personal consequences.
If they make a decision that leads to 50 clotting deaths but saves 5000 people from COVID as a counterfactual, their head is on a chopping block because those 5000 foregone deaths are invisible but the 50 deaths are visible.
If they make a decision to halt the vaccine distribution and this kills an extra 5000 people - well that's no problem because they were just being careful.
Society has set up a political situation where there is literally only one choice that absolves the bureaucrats from a negative personal outcome. Of course they're going to go that route.
Personal incentives are incredibly powerful drivers of behavior, whatever the publicly stated reasons for an action may happen to be.
It may be the case that they've made the right decision, but we can't assume that it was for the right reasons.
