Geoff – I think you have missed a subtlety of the early warning process by suggesting that if you hit unforeseen ground then as you have only just become aware that you should raise it as an early warning. The whole point of an early warning is to have the chance to mitigate the situation – and in this situation it does not look like there is anything that we can do about it. If this has happened then it is a compensation event and should be notified as soon as you become aware, and in any event within 8 weeks of becoming aware. The last line of 16.1 states that a matter that has already been raised as a compensation event does not need to be notified as an early warning matter. Following your example through you would have to raise an “early warning” as soon as you became aware of 1 in 10 year weather, lack of access etc which would be little help to either Party at that point.
However, if you hit unforeseen ground and you think that it may be an issue going forward for that area or another future area of work then that would be a worthy early warning as it might be something you can do something about – e.g. carry out investigative trial holes, surveys etc.
The rest of your comments about compensation events are very good I agree with 100%, and I believe are additional rather than contradictory to anything I highlighted within this original answer.