The fact is that we currently theorize that ALL species evolved from a common ancestor by means of natural selection and random mutations because of evidence that shows that SOME species evolved from a common ancestor by means of natural selection and random mutations, and, using Occam’s razor, we can infer that the conclusions from this evidence apply to other species as well.
There isn’t really evidence that ALL species evolved from a common ancestor randomly/naturally, but we conclude that they did because of what we saw in SOME species. But, there’s always the possibility that we will find something that was designed among the millions of things that evolved naturally.
And there's always the possibility that there is an invisible pink unicorn hiding in your ass which is the source of all gravity in the universe..
It's "possible".
Do you have any REASON or EVIDENCE or MECHANISM or even SUGGESTION that leads you to the conclusion that "maybe something was designed but we haven't found it yet"?
How is that argument any better than: "Maybe it was all designed to look like it wasn't designed?"
So, ID and evolution can both be working simultaneously. Therefore, evidence that X evolved is not evidence that Y wasn’t designed; and, evidence that both X and Y evolved is not evidence that Z wasn’t designed. And so on.
Follow the logic in your criteria.
There are two sets.
Set A: Those things for which we have evidence (includes evolution through natural selection)
Set B: Those things for which there is no evidence (includes Intelligent Design)
Set B _ALSO_ includes EVERY SINGLE THING THAT ANYONE ANYWHERE AT ANYTIME CAN MAKE UP ON THE FLY.
So, you are claiming that because we haven't collected evidence from EVERY SINGLE SPECIES on the planet, it is possible that Set B could be happening at the same time as Set A.
Why not take it a step further?
Since we haven't collected evidence from any single ORGANISM which is currently, was previously or will potentially be alive, we can't say definitively that Set B isn't occurring.
And, since we can't determine which of (infinite randomly combined words) is "true" they must ALL be EQUALLY valid.
So, on the one hand we have evolution, tried, true, tested and the basis of biology. The cornerstone of science for the last 150 years. A fact so rock solid that if it were disproven we'd have the throw out literally _ALL_ of science entirely.
And, on the other hand, we have EVERYTHING ANYONE COULD EVER SAY.
ID is as likely to be true as "Burp Rocket Cow Meteor".
Can't disprove "Burp Rocket Cow Meteor" because you haven't collected evidence from EVERYTHING EVERYWHERE across all of time past present and future.
Let's teach Burp Rocket Cow Meteor in school! YAY!