Just to note that there were no witnesses to a miracle by the way. There were (perhaps) witnesses to someone who appeared to be Jesus appearing to be dead, and there were (perhaps) witnesses to someone who appeared to be Jesus walking around fresh as a daisy three days later. The miracle part though - ie, stopping being dead - would have been in the tomb with a big rock in front of it. So far as I know there was no-one else in there to do any witnessing.
So, at best, what we have is people witnessing the setup and people witnessing the reveal, some of whom then reasoned that there must have been a miracle in between, only no-one saw that bit. And this, oddly, if precisely how a magician works - lots of attention on the setup, quick hiding behind the curtain, clap like fury at the reveal and leave the audience to decide that some magic must have happened behind that inconveniently placed roc - er - curtain.
Funny that.