User blog comment:Godisme/San'ou/@comment-4903773-20120726160542/@comment-5331679-20120726170013

They had a second member of Stern Ritter there, presumably with a medallion, who didn't know Renji could use a Bankai despite interrupting him in the middle of activating it (aka. Captain Clueless). Doesn't mean that they can't absorb multiple per medallion, but there's no real implication that they could.