From my understanding, they weren't entirely separate supply chains, since the contracts featured plants in the UK, just like the UK had plants in EU to fulfill

From my understanding, they weren't entirely separate supply chains, since the contracts featured plants in the UK, just like the UK had plants in EU to fulfill their contract. You're saying yields weren't sufficient when some plants weren't even submitted for EMA approval until late March 2021, that's few weeks ago. And looks like it was submitted after the EU pressured them to, or let's say, when it came to light. Which was quite convenient because such vaccines wouldn't be subject to export controls. If they have no legal leg, why are they sueing? To show the world they lost a case lol... if they are suing they feel like they have a clear case.