Jon, the reason you haven't heared of it before is because it didn't happen. This story appears often around Easter in one form or another. I have not seen the video but two years ago was contacted by a producer working on a program of German attrocities in Belgium during the 1st war regarding this supposed incident.
The producers had copies of three sworn statements made by soldiers during a court of inquiry who said that they had seen the crucified soldier. None of the statements described the same scene. None mentioned that the soldier was wearing a kilt. One said that there was a forage cap with a Maple Leaf badge on it laying at the soldier's feet another was a known liar and slacker who's veracity was in doubt.
The Canadian War Museum has researched this subject and has found no basis of fact about the claim, they also have the bronze depiction of the scene in their possession.