Sue, I had to give this one some thought! If I read it right, when you saw the internal temp of 114, at 5 pm, the smoker was still on. Since you only had another 8° to your target temp, my guess is that y'all got busy greeting guests, and that it actually went off later than 5:15...but I may be wrong. I doubt you would have reached that 8° in 15 minutes. At any rate, not watching (when getting close) was your downfall. I suspect it hit 122, and shutoff, as it's supposed to, but you just didn't get back to it before it continued to cook. These smokers are very tight, and well-insulated, so they hold the box temp for a long time! You didn't mention what time it was when the temp showed 146°, but I suspect it was much later than 5:15.
Kari, I disagree that the programming is a "detriment;" you just have to know what you are trying to accomplish, and be there to monitor what you are trying to do! I've said it many times, before, that the programming is a great tool, but it's not total "autopilot!" Inspect what you expect!
Gregg - just a side note: The "small cut" crazy timing really doesn't apply to this type of smoke. Lean beef roasts (other than really small briskets), smoked low and slow at 200°, are actually pretty predictable. There isn't a stall, and the climb stays pretty consistent.
Bottom line (for all):
Check on your smoke! Don't rely on programming, or how long you "think" it should take. Monitor, and adjust accordingly! Use a remote thermometer, with WiFi or Bluetooth, if you can't check on it frequently!
Oh, and for those of you waiting on the Meater.... I'll soon be testing a WiFi/Bluetooth/Cloud remote thermometer (with graphing) that I believe is going to be superior to the Meater, and much cheaper....more to follow soon!