Aishes, still illogical BECAUSE he has no gurantees with choice #1 but he knows that choice #2 is going well. And as far as any shadchan is concerned, since who ever that is knows that he is dating since he had been ready when choice #1 wasn’t the first question that shadchan should have asked was “are you currently busy, or in middle of a shidduch?” If he answered “no” then the news about choice #1 should have been relayed however if the response was yes, I am almost holding by proposing then the shadchan should have said “zai matzliach” and wait to see what happens”.
The fact that the shadchan relayed the availability of choice #1 caused tremendous trouble and issues for all three families. Choice #1 is innocent and not liable in anyway nor is her family however when the truth comes out that this young man backed out of a shidduch to date her, they will feel awful and they will never trust him. They will be very wary of his character. As far as choice #1 she might be flattered at first but she too will see fault with his character.