The "evidence" on here is nothing but annecdotal nonsense, without each of the cases being documented and confirmed as being frame-caused rather than post length or rider weight caused etc, I think you'd struggle to force anything under laws.
Fair enough, you only have my word (and photo) for what happened to my frame. Anyway I'll try and give a clearer picture of what happened with mine. It was a large frame with a 420mm seat post. It broke while within its warranty period. I contacted the bike shop that sold me the frame (Evans) and they spoke to Pace. The frame and seatpost went to Pace for inspection.
Pace presumably decided that I had run the seatpost inserted an adequate distance as I got an RC305 frame back. However I had decided that I'd prefer a different frame, partly due to a lack of confidence in the Pace frame and partly because I found it too short horizontally, so I sold it. I then spent about a year not really getting along with a 20" Scandal before getting an XL Chameleon and living happily ever after. 🙂
Before I got the RC303 I had a 19" Cotic Soul. Again I had a lot of seatpost showing but that frame coped fine. Personally I feel that because the RC303's top tube was dropped so far on the large frame size that it was a bit misleading to call it a large frame. It was reasonably long but because you needed a vast amount of seat post inserted it really limited how high the saddle could be.
Perhaps if there'd been an XL or even an XXL size I may still be riding one. 🙂