It can be difficult to predict whether there will be problems with the search at the European Patent Office (EPO), either in terms of lack of unity or lack of clarity. Incomplete searches will impact tremendously on the scope of claims that will be granted.
One never knows which terms will be deemed unclear in claims. This varies tremendously from territory to territory, with Canada being one of the strictest places on clarity.
Many surprising things happen at Oral Proceedings. Certain documents or arguments may suddenly become more relevant. How the different parties will perform and whether justice will be done seems to vary markedly.
How to evaluate the worth of a patent case remains a very uncertain art. However what it is clear is that investors at getting much better at evaluating biotech patent cases.