In one scene in this movie, our hero must convince a religious cell mate in prison that he has just experienced 'stigmata'. In order to achieve this, he jumps back in time to when he was a child, skewers his hands on two metal spikes and having changed history, jumps back to the present. The previously skeptical cell-mate witnesses the scars appear on his hands and is convinced that he has just witnessed something miraculous.
If this actually happened then he would have changed history so that those scars would always have been there since that time he made them. When he arrived back in the present, as far as the cell mate would have been concerned, those scars always would have been there.
Someone hasn't thought this through.