Will's explanation that the blood selection process is not based on science is incorrect. The blood screening test is not 100% effective. Therefore each of the risk factors increase the possibility that blood is unsafe. Scientific Statistics would dictate different risk factors result in the chance of blood being safe for use would be below acceptable risk criteria.
Will would not have been able to donate blood since he falls under the category of men who have sex with men who, at the time, could not donate blood unless they abstain from all sexual contact for a period of 12 months.