I think it is the use of sauna that ban him from fighting and due to that, he was unable to defend his title twice which resulted in him being stripped of the title.
The bottom line is, that Casimero is having a weight problem issue that leads him to use the sauna. Aside from that, his camp was unaware of that policy under British Boxing Council. If only they are responsible, Casimero should be the one facing Inoue now. Don't want to happen the same situation with Jerwin Ancajas.
Back to topic, and as I previously posted
here, Ancajas camp admits that they overtrained Jerwin just to meet the required weight. That's why to solve that, they will cut Ancajas' training volume.