It was a different Bobcat. AFAIK, while LE went to that site and did some digging, they did not impound or inspect that Bobcat. It's possible the noise heard by the neighbor at that site (which is on the edge of Salida, miles from Puma Path) was something completely unrelated. And she wasn't sure if it was Friday or Saturday night.
I'm now wondering if LE thought it strange that Barry's own Bobcat had a brand new shiny blade on it, almost as if he was trying to make sure that the blade contained no evidence. Actually, I'm pretty sure that LE must have thought this. But I have always wondered why they didn't impound that Bobcat to take a look at where it had been recently, through soil and other analysis.