So they answered Jesus, “We don’t know.”
And Jesus said to them, “Neither will I tell you by what authority I do these things.”
As is typical for these men this ‘non-answer’ is still a lie. They don’t know? This must be about the only thing ‘spiritual’ to which they admit ignorance. Of course they did not believe that John the Baptist was from God. They modify their response; i.e., lie, in order to further their agenda against Jesus. Even in their apparent ‘lack of knowledge’ they are ‘ends justifies the means’ liars.
The end never justifies the means. Never.