I partly see this from a different perspective.
Sure, a crown is a 'standard' part for any watch. Certainly, it can fall off (and this happened also to one of my watches). Rightfully, one is particularly embarrassed if this happens with such a highly acclaimed piece as your Journe.
That said, I personally find it to be acceptable (and common practice) in such a case that the manufacturer offers to have the watch repaired. I do not see a reason to have the watch exchanged because a minor part (minor in the sense that failure of this part does not imply that the entire watch is defective or does not meet standards) fails.
I do not know the pre-history of this case nor do I have insights into the standard service practice at Montres Journe so I abstain from commenting on the financial arrangements. Also, I do not know to what extent Mr Journe himself was involved.
Did you discuss the matter with Brad Schwartz (bs22fly), moderator of the Journe forum, first?
Thanks a lot. I'd be happy to help and to learn more about this matter.
Thanks,
Magnus