Not so sure that it is "highly unusual" tbh, particularly in...

Not so sure that it is "highly unusual" tbh, particularly in scenarios such as this where overall sentiment has been so negative and other forces seeking to exploit this are playing out. Do I like it - no! But it seems overall to be a not so uncommon state of affairs with loads of speculative higher-risk stocks.

Do markets always price in a positive % success on a drill? No, I don't think they always do. In this case, I'd say the market is not going to price anything in until the result is known. IIRC the COS on ED is a bit of a coin toss. In this case, it's apparent there's been little to no market appetite or excitement generated at all over ED as overall sentiment remains poor post SE2/3 and a negative outcome will almost certainly see more short-term price pain. No one is going to play ball until the result is known.