I would say that you are presenting what's known as a "false dilemma," i.e. your statement assumes that there are only two possibilities: either (1) I have the evidence in which case it costs me nothing to present it; or (2) I don't in which case it is dishonest for me to offer to present evidence.

Of course there is another possibility, which is that I am reasonably confident I can present the evidence, but it will take me time and energy to gather and present it.

For example, suppose I bought a toaster a month ago; it breaks; I call up the store to get it fixed; and the store manager says "We can't help you since you aren't the original purchaser." Before I spend 20 minutes finding the credit card receipt, I'm going to ask the guy "Would you like to see proof that I bought the toaster?"

I think that when I asked "would you like to see some evidence," the reasonable interpretation is that I can gather and present the evidence with a small but non-zero amount of effort.

However, if you did not understand my comment that way, that's what I meant.

And again, it would have been easy enough for the other poster to say "Yes, I am skeptical of your claim and would like to see the evidence." Since he didn't do it, I infer that he doesn't want to invest any further energy in the interaction. Which is fine, but if he doesn't want to invest further energy, I don't want to either.