I don't know about you "losing the plot", SS, but you do seem to be misunderstanding what I said.
To clarify, I said that meat, other than lamb (e.g. beef), CAN be used to make a keema naan, whereas Jerry clearly stated that "no other meat will do". Other meat WILL do, in my opinion, and many people might find it preferable to lamb.
What I do not dispute is that most BIRs appear to use lamb in their keema naans.
Similarly, basmati rice is not the ONLY rice that "will do".
Whether ALL BIRs use lamb in their keema naans, and ALL BIRs use basmati rice (there are several reports here to the contrary), I really couldn't say.
Maybe Jerry meant to say that only lamb (in a keema naan) will do for him (which is presumably what you are also saying).