I am so sorry for your loss - one of my cats (age 13) has had Rimadyl both via injection and tablets (although I was told by a second vet not to continue with the Rimadyl as the dosage was too high), and have had no probs with it, I certainly wasn't warned about it. Cats can actually lose up to 75% of their kidney function before any symptoms show, so it could be that she did have issues and you didn't know about it. I dont think you will ever know, but you didn't cause this, you were getting her treatment. You could try complaining to the RCVS, but they dont have a good track record for doing anything about them sadly. I am puzzled why he would give an anti-inflammatory for a runny nose though, surely giving something like anti-biotics would have been better.