An alternative hypothesis is that the lots are identical, but something else like the patients, refrigeration, or administration negatively varies a lot.

We know that mRNA will get taken up by whatever cells it bumps into. Injected into your blood, it converts blood vessel cells, heart cells, or any cell that has a direct interface with the blood into spike factories to be killed by the immune system. If you have a microbruise, which happen all the time, it can get into any organ anywhere or into nerves.

So I think this shows batches going to places with different standards of care. One batch goes to Walmart where the technicians just jab it anywhere in the general vicinity of your arm and lots of people get it in their blood and die. Another goes to a hospital where actual nurses aspirate the needle and most people get it in their muscle.

Or vice versa, sometimes the people that do it everyday are better at it than the people that just studied how to do it. If administration is a big factor how would you even know where to go to have the best odds? I don't know.