Probably a flaw in the fabric. I ended up on the ground late last fall when the bottom of mine literally blew out. A bad feeling, especially on a rainy, cold night in the mountains a little north of Big Timber, MT.
I'm also 150#. This was a professionally made hammock and was immediately replaced by the vendor. I sent them the torn one and they had never seen it happen before. I'm also very careful not to have anything sharp or rough attached to what I wear to sleep in. Had fleece pants on then.
Love is blind. Marriage is an eye opener.