Global got "caught" in the late-running football game. When it came on at around 8:22 pm, it was unable to simsub "24" in HD. It is running SD now. I've been watching WUTV Buffalo in HD since 8:00.
Put it another way, the only way Global could be simsubbing at 16:9 would be a football game finishing on time. Then it's a matter of putting it's lousy logo on top of Fox's.