[@mention:456308404254624012] Instead of the invalid or not valid line you might refer back to the agreement we made as an organization when adopting Holacracy.
So a line like "So you just told me that your objection is not in line with the Rules we agreed upon" might do the trick.
Myself I use the line Brian uses but with the addition where I refer to the Rules. "So you just told me your Objection is not valid according to the Rules of the Constitution". The reason for this is that it provides me an easy way to refer to art. 3.2.4. when asked "Why" and it directly aims it at the Process and not the person who is facilitating (no judgement from the Facilitator).
Interested in your learnings and the way forward you take.