Chris,
It is not about you. It is about trying to help hunters who are looking for information, and giving them another tool in the tool box to use when trying to prepare for a hunt. I have been blessed by God many times over. I go on more big game hunts in a year than most will go on in a lifetime. However, that was not always the case and when I went on my first approximately 30 years ago I wanted to do everything I could to make sure I was prepared including shooting the right bullet. So all I wanted to do was let someone who is not as knowledgeable as you know they might gather some good information from guides regarding bullet selection. I agree some guides are not a wealth of information on bullet selection, but I have to say the ones I have used over the last 10 years or so have been very knowledgeable.
As for the video, I watched the shot on video. I do not have the video. It was taken by another guide, not my guide. With all due respect, considering how this thread has went I am not going to make any effort to find out who the guide was and then ask him to send me the video so I can upload it and let everyone Monday morning quarterback critique the guys shot, etc. The hunter was very upset he lost that goat.
Since you have never killed a goat, I am assuming you have never walked up to a dead one in late season. I am attaching a photo of one of the goats we watched last week. Those big billies are covered in shale, dirt and ice that time of year. I am not an engineer. All I know is that they guy hit the goat at 600 yards and he did not kill the goat that day. They said the goat walked away. They looked for the goat. Where it went I do not know. If you go on a goat hunt, and I hope you do get the chance if that is something you would like to do one day, use whatever bullet you want to use. I shot mine with a 180 grain Berger VLD and it worked perfectly. So best to you and yours.