Question: When Baxter and his men ride into town, he brings 8 hired guns with him for a total of 9; but when the fight starts, there are only 8. Baxter and 4 men confront Charlie and Boss, in the street, and 3 go round behind the buildings. What happened to the 9th man?
Answer: I believe he is the one being chased by the townfolks, after the gunfight is over.
Answer: I noticed this as well. The person shot at the end of the film is the same man that was with the sheriff when they were held in the jail. He was a deputy and did not ride in with the land baron.