Very emotive thread.Pilots must watch out for each other.However,the way you do it is almost as important as the cause of your concern.Never openly contradict another professional on an open frequency.Make an observation and repeat it until you've been heard loud and clear.If hes as professional as you are,he'll heed the warning.In this case,the Iberia pilots would have responded with"Thank you for your advice.We're going to make another inspection and review our decision."
If you intercede indiscreetly and aggressively,you end up defeating your own good intentions.Privately,you might be fuming,but always follow the protocol.There are exceptions to the rule of course(like witnessing a line-up on a closed/wrong runway).In that case,protocol be damned and you do what must be done.
Additionally,by naming the airline in question,the company could trace the crew in question through the date and type of aircraft.You were right to post but should not have mentioned the airline in question.