"As commander sometimes one is not in complete control of the R/T! I have had a couple of occasions fairly recently where my colleague has asked (without reference to me!) "Do you still require us on this heading?" and also "Are there any level restrictions at XXX today?" - one doesn't want to spoil the decorum on the flight deck but not consulting with the commander before making superfluous R/T calls is also one of my pet hates, notwithstanding CRM!"
Though it may be the commanders privilege to say whatever he wants on the radio, I must say it works both ways. It can be quite an embarrasement when the guy who's supposedly in charge can't hack the R/T... As for asking things to ATC before consulting the other crewmember, I think the worst one is: "field in sight"...
/LnS