I don't see what else would be convincing. Specific jobs held, where schooled, are irrelevant to the judgement of expertise. For that, they don't even need to know the guy's name.I don't know how I could have been so blind! Of course it doesn't matter whether we know anything about this anonymous guy, sine the anonymouse customer trusts him!
Or, rather, Rossi says that the anonymous customer trusts the anonymous agent.
How could anyone doubt Rossi with that kind of rock-solid evidence!
Stop dodging the point. The OTHER outside experts who were attending the demostration were judging the TECHNICAL QUALFICATIONS of the evaluator. The anonymity of the customer, the evaluator, and anybody else matters not one bit with respect to making that judgment.