I guess the way I look at it: "Is this loss sustainable?"
What I mean by that is it felt much like a Bears win, but on the other side of the fence.
Detroit had a punt return (not for TD, but set up very short field). Detroit had an INT return (not quite TD, but close enough). Detroit had fumble return for TD. Detroit had long TD run on broken play/tackle.
What you have to ask yourself is "Can these things happen on a consistent basis against the Bears?" If your answer is "Yes", then The Bears are in trouble. I do not think all of these things happening in one game can happen on a regular basis.
I tend to think that these type of games happen. The Bears are normally on the winning side of these. hell, just look at last year. As soon as all the "breaks" stopped happening (like INT returns or kick returns) the Bears started losing.
I think a game like this, fairly early in the year might be a good thing. It will make the Bears realize that there are certain things they cannot do and need to tighten it up a bit.
IMO, this is any but the "same old Bears".