Reject away lol, you wern't there. I have had quite a lot of cattle dogs over the years and I can assure you I know the difference between wishful thinking and reality. The majority of my cattle dogs would not have engaged an attacker, but I have had one that most certainly would have and did and I thank her to this day. She had good bite inhibition but when it came to a threat she was a very different dog. I travelled a lot of far flung places with her riding shotgun and if you had bad intentions towards me or my property she was not a dog to be messed with. She was a very high drive, strong smart dog and she definitely had good bite inhibition and would give warning before going up to the next level, so she is not the type that you are likely referring to I would think.
I know the protection thing is highly debated, but I have been around dogs a very long time and have most definitely seen examples of this. So I know it is not wishful thinking.