It's rather embarrassing
Imagine the scene. Sitting at some high powered sales meeting.
You have a few misunderstandings with your strange colleague but miraculously they bid the perfect contract. Makeable, top.
The competitors are competitive and preemptive so you double for your partner to say what they have to offer and you are happy but want them to shut up after that.
You pass, happy with the outcome only for them to start competing in an impossible contract when a competitor interferes
You try desperately to escape the disastrous enthusiastic junior bid by bidding what they had. Another possibly makeable better contract
But they take your escape attempt as a cue and keep going in a different direction with something you aren't strong in
You decide not to risk another cue and risk enormous penalties
When the cards come down you just throw in your hand and walk away
Oops here is the hand. You always feel guilty like it was your fault. But upon review I don't think my bidding was that bad. In my book double followed by pass is agreement or at least being reasonably happy etc
Fortunately me and GiB are not in business together