I don't give monkeys if Keith calls me a Liar.

He still hasn't grasped the concept that the one who provides the hypothesis bears the responsibility of providing evidence.

If he can't provide the evidence then his hypothesis is groundless.

If, in addition to this, there is unbviased evidence that contradicts his hypothesis, then he looks like he is either biased himself or a moron.

There is plenty of evidence to support both hypotheses.