Or a passenger who was used to United's long standing hold policy that did allow exactly that and without any regard to one's mileage balance.

I think it isn't reasonable to expect everyone to be familiar with Continental policies that now all of a sudden are United policies. (Based on the other responses, is it safe to assume this is where the policy came from?) At a minimum, good customer service would have been to say "I know we used to allow this in the past, but we now have a new policy bla bla bla." One more reason I am glad I am not flying UA anymore

Also, ouch about the tone here these days.