If you're not denying the possibility, then what exactly are you trying to say here? That you're skeptical that the experiment detected anything, or that the "anything" it detected is what they are saying it is?
Clearly the first can and will be found out over time as other detectors are being built to replicate these findings. However, I believe there is enough scrutiny of their claims that this kind of skepticism can likely be ruled out.
The second, that their story doesn't fit the data, is kind of odd to me. Gravity is so weak and the detectors they are creating are still so new that it seems likely that colliding massive bodies would be the first kinds of things they would pick up. Just as with early telescopes where objects that were very close or very bright were the first ones to yield useful data.
If you have another explanation that you believe fits the data better, put it forward and try and find a way to test it. That's how science works. But this is not the kind of thing that is going to collapse in a heap of logic. Data and the scientific method doesn't work like that.
