In my reading about Columbine, I've come across different stories about where the teacher Dave Sanders was shot. "In a hallway on the second floor" seems to be the only thing some of the stories have in common.
I know he was shot twice in the back and one of the shots clipped a major blood vessel in his shoulder. Also, the lead investigator said that they are still not certain whether Harris or Klebold did it.
You watch the cafeteria surveillance video and wonder how this man getting close to 50 was better than the Uvalde SWAT team.