That doesn't necessarily mean they'll behave responsibly on the phone. I actually work somewhere that telephone calls are recorded frequently. You eventually get complacent and don't even think about it. It isn't far fetched that someone says something incriminating even with the prospect of the call being recorded.
That is modern journalism. They throw [Mark May] at the wall and see if it sticks. They heard something from someone, they ran with it. There may be truth to it or there may not be.
What I found even more peculiar was that I read somewhere when all of this was going down that they had known about it that entire time but had not been able to verify it. Which, I think, is the most likely story here. It would seem like quite a leap to say we were trying to sweep it under the rug.