To be honest i dont really think you are in any position to blame Sammy Miller for the levers breaking. What do you expect to happen if the bike is knocked off its stand ?
I have dealt with Sammy miller for all my spares for the last 14 years and have always had excellent service.
As for the comments on his mannor whilst dealing with customers in his shop, i doubt anyone involved in the motorcycle trade has as many people competing for their time as he does. I wonder would the people posting such comments be able to run a mail order business, a shop, bike museum, restoration workshop, fly all over the world competing and showing bikes whilst still giving up as much time as people require from him. I very much doubt it. Its always very easy to criticise someone who is well known and very successful, but who else can say they have acheived anything close to that level ?