At present REH is responsible for ALL the development costs of...

At present REH is responsible for ALL the development costs of CETO until approval by CNM shareholders.
They may be using this avenue to fund the development of CETO up to the date of the CNM shareholder approval meeting.

On REH's web site one of the restrictions may be.
"If required by Chapter 9 of the Listing Rules of the ASX, REH entering into a restriction agreement in relation to its 32% holding in Carnegie which may restrict REH's ability to trade it's shares in Carnegie for a set period of time."

In the Northern Hemisphere Carnegie will co-develop CETO with EDF EN, a 50% subsidiary of one of the worlds largest power companies. To me this puts REH on the side line apart from the 32% shareholding and board representation.
EDF EN is in a much better position and larger company than REH. They also will have contacts in the right places.