Poor Tilley, and what a dreadful experience for both of you
I've just read your link and from that followed the link to the training club and from there to the ADTB website, which says positive training methods only. I also noted that the training club does the Kennel Club Good Citizenship Dog Scheme.
Have you considered contacting the ADTB and the KC to report the incident to them? I very much doubt it was a one off as the trainer had his/her rattle bottle to hand. Right now I feel very angry on your behalf. What the trainer did was just so wrong. It doesn't matter how over excited Tilley was being, it was ignorant, irresponsible and damaging for that trainer to treat her so badly.
Modified to add - the ADTB website, which lists your trainer, states the following -
"Our Instructors are aware that only kind, motivational methods of training dogs will be tolerated by the ADTB and that any trainer approved by the ADTB would be instantly dismissed from the organisation should any report of harsh handling or cruelty be proven. ADTB Instructors should not bring the good name of the ADTB into disrepute."
I really think you should complain direct to the ADTB.