Exculpatory evidence: a videotape that shows the defendant was 50 miles away at the time.
Rebuttal evidence: a videotape that shows that the witness who claims he saw the defendant commit the crime was 50 miles away at the time.
Without that witness's testimony, the rebuttal evidence is meaningless.
I'm wondering what video the prosecution wasn't aware of. (Does the "knew or should have known" standard apply?)