It's not the risk of clots. It's the risk of vaccine hesitancy because people fear a cover up. I think that's outweighed by the increased vaccine hesitancy because people only hear this scary story and not the low numbers (see also AstroZeneca).
Unfortunately this "pause" will also result in vaccine hesitancy (on top of vaccination delays). We know this from the EU experience with the AstraZeneca vaccine which is now distrusted by many people.
This will almost certainly now be a problem with the J&J vaccine in the US. More people will get sick and die because of this.
