Honestly, if you had actual, irrefutable, empirical PROOF for evolution, Hovind would pay up.
Would he? I don't believe he has the money. 250,000 is a lot of money. And anyway, the fact that Hovind hasn't paid his prize doesn't mean there's no proof. He could just be a liar, for instance.
Anyway, he's making his wager with the full knowledge that science can never "prove" anything absolutely. The conclusions of science are always tentative. That's why science is able to create better theories in the face of new evidence. No religion I know keeps such an open mind.
Fossils, radiometric dating, and the geologic strata would not hold up in a court of law as PROOF for evolution--consider the OPEN-MINDED creationist to be the Jury that will decide whether or not substantial evidence exists for evolution.
In the face of things like the O.J. Simpson trial and other miscarriages of justice, do you really think a court of law is the place to test scientific reality? If so you must put a great deal of trust in lawyers as honest, truthful individuals.
If we evolved by chance, how would "evolution" know that we would be in need of a thumb millions of years down the road?
do you think that ancient man didn't use his thumbs? Why do you say "millions of years down the road"? When the fifth digit migrated down closer to our wrists it would have had immediate functionality. Thumbs are immediately useful for tool-using animals, as we are. Other animals (like pandas) that grasp things also have thumb-like protrusions. I've seen housecats with thumbs they can't use. (well, they look like thumbs to me.)
Better yet, since the only function you've postulated for the thumb is to use a keyboard: why do primates have thumbs? They don't have keyboards. Why did your god give them thumbs? (They have thumbs on their feet, too. Why don't we?)