The key point here is ""ensure all aspects of the technical specification are met". So unless the manufacturer has provided you with the full specification and any testing they perform then you do not meet the requirements.
Also did you cost in all your time into the equation? This is not just the time you spend finding the part but all the documentation and testing to ensure you fulfil all the requirements. In the end it is just cheaper to buy from the manufacturer! Better to spend the time negotiating a good price! As I said the role of EBME is evolving so embrace the change!