There is nothing unusual that Craig Penrice was paid for his time and from what I have read he aquitted himself professionally and as you would expect from an expert witness.
All expert witnesses are paid for the time just like everyone else. They are expected to abide by well established rules of conduct, and are, and are expected to be, indepependent of the party calling them.
The whole point of independent experts is that you may not like what they say (whether you are cross-examining them or calling them) but their evidence is rightly given considerable weight.
All that said, some experts are willing to put their heart and soul into a case, whilst still remaining independent - again from what I have read Craig Penrice did just that - as such Spot and his team were lucky to have him - as was the CM as a whole as part of the process that resulted in the justified outcome.