Alignment - SAI Question

Hey everyone,

Got an alignment done today, and I was able to sit there while the guy did it in the bay. Was cool to see how everything works. On the Hunter machine, as he was adjusting toe towards the end I believe, there was an "SAI" reading at around 12.8. It was in the red, meaning out of spec. Granted, this wasn't a final reading, just something I saw on the computer screen. However it was towards the end when he was tightening things back up. The final alignment print out didn't have the SAI or Included Angle numbers on it so IDK what those final numbers are or if they matter. Anyways, just asking about it!

 

I should also say after reading about SAI online, it seems to point to damage and things being bent. My truck is babied and never really took any big hits. I also just had an offroad shop recently look over my suspension and tighten/lube things up and they said it all looks fine. Other than damage, what other things can make the SAI reading be out of spec or in the red?