Winnebago roof blows off

I remember having this conversation with my local dealer when the topic came up about TPO vs fiberglass. I remarked that most people think fiberglass is better and a lot touted that Winnebago puts it on theirs. My dealer tried to educate me on the way the Winnie roof is put on and that it can come undone. I really didn't get it at the time, but it makes more sense now. I remember having the TPO/Fiberglass debate on here a few times and some folks being pretty adamant about having to have fiberglass.

I know 2 things coming out of this thread, That apparently the Winnie roof can come off, and that it's probably several times more expensive to fix than a TPO.