Bo had alerted about an hour earlier on a low. Austin was 83 at the time and I gave him a 25 g carb ice cream snack and didn't cover it with insulin. So, when Bo alerted low for a second time, I thought he may be confusing his alert chains. (He isn't 100% accurate in his use of the high and low alert chains yet.)
I removed the tether and took Bo outside to check Austin. Austin insisted he felt fine and he didn't need to check. For a fleeting moment I second guessed Bo but then I told Austin we had to check because Bo had alerted. It's a good thing we did because Austin was 68.
Bo got a big low party for this alert and after the party he went back to his cot and went to sleep.