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: The man you see being shot at in the end was the man who ran off once the sheriff had the kid, and Baxter was going to kill him. So, just before the shooting started again, this man ran off away from Baxter. What you see the townsfolk shooting at is this man who ran off just before the end, where Baxter and the sheriff had the boy and were counting down.
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.
Answer: I believe he is the one being chased by the townfolks, after the gunfight is over.