I agree with @bnb6 that I wouldn’t consider there to be risks with the V&V process itself, but rather the risks if there was a problem during the verification stage or even the verification was completed successfully that the device could be properly validated. For example maybe all the specs are correct and the design outputs are equal to the design inputs, but maybe during the pilot clinical trial to validate in the a surgical device isn’t what’s needed to fit the patient’s need of that the devices needs to do. So then maybe some tweaks would need to made in order to account for this and this could as @cdj24 mentions, add delays and could extend the time/cost of your project.