LHR - gate A10 on Sunday for YYZ was confusing.
Old boarding process was announced. Then when the first person was getting turned away the new process was announced. But the person who was turned away was WTP with no status and promptly walked to another desk and was let through.
Plenty of yellow tags in evidence - but a bit of a half-hearted attempt at applying them at the gate by a lady who wandered through the crowd and applied precisely one more tag - and walked straight past me with my 2 pieces (and no yellow tag) without checking my boarding pass.