"What would be a good way to distinguish the hypotheses?" - Virginia-American
A good way would be to see evidence in the lab of DNA self-forming (i.e. Evolution or Abiogenesis) or being formed by Man (i.e. an Intelligent Designer), but I wouldn't be so bold as to claim that that is the only way to distinguish the two (although I'll leave other examples up to you).
Perhaps it would be the same sort of intelligence that would put ancient CP/M code in the kernal to Windows NT
Perhaps there's a Designer, and perhaps he codes like a person rather than a Deity, and perhaps...
Perhaps Occam had a point.
So you claim ID first predicted fast speciation. Where? Genesis?
Intelligent Design was born late last month and didn't scoop punctuated equilibrium on anything, unless you're buying off on ID = creationism. Not that I don't think it is, but part of the ID mantra is "Creationism is a strawman!"
The punctuated equilibrium model still says Thing A comes from similar Thing B in fairly smooth steps. (If you can find where to dig for the smooth steps, assuming they even got fossilized.) It can cite evidence from the fossil record that things do happen that way.
Note that in the preceding examples, you can see the changes happening smoothly in one place, whereas they appear abruptly everywhere else (from migration). It makes sense and requires no assumption of supernatural elements.
Which is what ID-er's don't like about it. ID isn't about explaining anything any better. It's about getting rid of those nasty naturalistic explanations.
I don't see where ID offers comparably testable or already-supported content.