There is nothing termed a CD arrival at LHR. A LAM3A arrival, maybe, but not a CD arrival. However, there is a continuous descent noise abatement procedure so I guess you were referring to that. Maybe the guys in the other seat were wondering what you are on about.
I expect that CRM training featured at some time in your career, so its a shame that the principles of teamwork seem to have passed you by. Your antipathy and lack of support for the older captain is downright dangerous and completely unprofessional. Nobody is perfect, not even you, and your attitude is likely to make you and the guy unfortunate enough to fly with you another accident statistic.
Its also a completely arrogant assumption that the over 60 pilot never had a career setback or stagnation. The airline industry has been through frequent recessions, several before you appeared on the scene, so your present setbacks are nothing new. Get a life.