Bitlocker was probably continuing to encrypt the drive. There's two options with bit locker one to encrypt used space and the other to encrypt everything. Perhaps you selected the slower installation method.
BootCamp cannot read encrypted Bitlocker partition and startup information(maybe). And thus it is not possible to support bitlocker on bootcamp.I know this is an old thread, but I'm hoping someone has some info. I created my Bootcamp partition and installed Windows 10. Bitlocker won't let me install - something about TPM configuration that I can't change. Some googling suggests that Bitlocker and Bootcamp are not compatible.
Other thoughts?
Thanks.