I'm not commenting on Dave as I've no idea what he said/wrote, I'm replying to the above as it's a commonly held point that the EU shipped does to the UK and the UK has not reciprocated. And this is very much not true.

The EU does not make any vaccine, and so by definition has not shipped any doses to the UK.

A private company (AZ) has contracts that include manufacturing in the EU and shipping into the UK.

This has nothing to do with the EU as an entity at all; it is simple private trade. If the EU couldn't come up with an enforcable private contract going the other way, that's on them. And even if AZ are somehow in the wrong on the EU contract, it's still private contracts between them and the EU and has nothing to do with the UK government, so why should it be 'obliged' to send any back? After all, the UK (as an entity) also doesn't produce vaccines and so has none to send in any event.