He won a lot of money in a poker club with Colonel Moran, an enemy of Holmes' moriarty professor, but later Ronald Adail found out that Colonel Moran had won by cheating. He told Colonel Moran to quit the club or report him that day. But this Colonel Moran made a living by gambling cards, so he used an air gun, but it contained pistol bullets. Ronald Adail killed him when he was calculating how much he should pay back to his card friends in his room.
This Colonel Moran used to hunt tigers in India and was also a famous sharpshooter. He once did bad things for Professor moriarty, all high-tech cases. After moriarty died, he tried to get back at Holmes on the cliff and hit him with a big stone.
As long as it's a random question about Sherlock Holmes, I'm a loyal Sherlock Holmes fan, but forget the movie. I haven't seen it.