How To Flub Prime Rib Roast

In an abbreviated Wallace Street Journal, David Bond describes a cooking mistake that he recently made:

I’ve made a few. First, most recently with a prime rib roast, which we do only occasionally now that an 8-lb prime has got up to the price of a used car. The recipe is quite simple. Pat the roast down with coarse pepper, stick it into a 500-degree oven for precisely one hour in an uncovered roasting pan. Turn the oven off and let the bugger sit for 3 and a half to-5 hours. Do not, ever, ever, ever, open the oven doo r. Then at the end that long sit, (you still haven’t opened the oven, have you?) fire the oven back up to 350 or so for about a half hour or so, depending on the rareness you want. Let the meat rest under cover of tin foil,, etc., etc. The mistake I make every time with this very simple cooking recipe is forgetting to remove the smoke alarm from the house. If you don’t, about 90 minutes into the cooking process the house will fill with fumes and the bloody alarm will go off, requiring a change of undergarments and sending the dog into the fan-tods .

Question: Describe the last cooking mistake that you’ve made.