No, that's not true. Once the offer goes unconditional (at 50.1%) RMS controls BRB. It will therefore consolidate the BRB accounts into theirs.
if unconditional they control the cash. 80% gets CGT roll over relief for BRB shareholders at at 90% compulsory acquisition is triggered meaning the last 10% immediately goes to RMS.
so 50.1% is the critical level.