Indeed it is possible but if you think there's a chance it did and the BBC still ran that show regardless, I have some shares in moon-stock to sell you.
I was also disappointed they didn't actually show what the proof was - this table on their site saying whether or not there was a side letter, why not show it?
I was wanting to see the evidence tonight not just another hint they're on their way to oblivion.
Most interesting tonight was the suggestion of D+P being at it. I find their response rather amusing, it's as if they think Mark Daly unilaterally decided to broadcast a national television story tonight with all kinds of libel issues with no checking, editing or legal reference. Good one.