I initially brought the issue up. I was unhappy with the way some things were organised and (not) part of my sphere of influence plus a set of other open issues. The initial thrust was to renegotiate, to set responsibilities and expectations straight.

We had an initial round of meetings and then the issue slipped with meetings getting pushed out further and further from the other side. So yes, I think that in this position the other person was in charge. In any case, even if I'd be responsible to push the agenda, a good HR department should not let an open (and known) issue slip. Quite, to the contrary, good HR should recognise situations like this before the employee ever feels the need to push for a contract renegotiation.