The way that top hat was designed and where TTD seats, it's not possible for TTD to get stuck. Cedar Point is surrounded on 3 & 1/2 sides by Lake Erie(one of the great lakes for those who don't know), and TTD is 420ft tall, so there will always be unstable air movement no matter what day you go on. It can 'stop' at the top, but the slightest move or breeze can send the train forwards or backwards, this is due to the design of the top hat. It will never get stuck and stay stuck. However if a simalar ride was built indoors, with no wind factor and no one on the train, then it could be possible, but the odds are very slim to none.
BTW, the reason for the catwalks and elevator is so they can do maintance on TTD. 420ft is alot of stairs to climb you know,
It's like any other coaster at CP, they do daily/weekly/monthly inpections of all track sections. A 450ft crane with a bucket isn't an easy thing to move around thru the park every morning,