According to Washington Post, comments were sarcastic

[Gothmog]

Rosenstein may have been responding to a demand by McCabe to open investigation on trump https://www.washingtonpost.com/world/national-security/mccabe-memos-say-rosenstein-considered-secretly-recording-trump/2018/09/21/f4aa9a62-bdca-11e8-8792-78719177250f_story.html?utm_term=.2869404721af

While McCabe’s memos assert both the recording and 25th amendment conversations occurred at a meeting within days of Comey’s firing, another person at the meeting, speaking on condition of anonymity to discuss internal deliberations, insisted the recording comment was said in a moment of sarcasm, and that the 25th amendment was not discussed.

That person said the wire comment came in response to McCabe’s own pushing for the Justice Department to open an investigation into the president. To that, Rosenstein responded with what this person described as a sarcastic comment along the lines of, “What do you want to do, Andy, wire the president?”

That person insisted the statement was never discussed with any intention of recording a conversation with the president.

Another official at the meeting, then-FBI lawyer Lisa Page, wrote her own memo of the discussion which does not mention any talk of the 25th amendment, according to a second person who was familiar with her account.

[eleny]

1. The plot thickens

It sure didn't take long for a contradictory assertion to emerge.

Hopefully, this latest will save Rosenstein and put the brakes on WH plans to oust him..

[lagomorph777]

2. The plot thins.

It was pretty weak from the outset.

[eleny]

3. All this he said - he said

But really, Trump won't dwell on the denials or the proof that the denial is the truth.