As the majority stated above, I do not think there are a lot of risk and default in the Validation & Verification procedures. The V&V procedures are “…driven by the regulatory environment and international standards.” As long as the procedures are done properly, I do not see any major issues. I agree with hc255, where an issue can be that the product design does not get validated and the plan has to be changed. This would be very time consuming and costly.

You can read more information on the V&V procedures on the asme website under Validation & Verification