It looks like the wood has split where drilled for the bracket, so presumably there was either a manufacturing fault or simply a weakness in the wood exacerbated by the bracket. However, early BRes had a weakness in their booms. I believe Swallow modified (strengthened) the booms but I don't know when that started and, hence, which version your would be. My 2012 BRe had an original boom and it bent under load - see photo. It went back to the yard for various bit of work and they strengthened the boom by adding a strip of wood underneath the existing boom. If yours has an original boom, it may be more prone to this sort of failure.