Tenant reports broken window (with picture)

[Loren Whitney]

Hey All, 

My tenant just shot me a message with a picture of a broken window (nice right). He says, "Not sure how this got here but last time I opened the blinds it wasn't there". I haven't been over to the property yet but i know thermal breaks are quiet rare, especially on a dark side of the house. Can anyone with Glass experience tell if this is a thermal break or a self-inflicted break? I'm about 90% sure its a dual pane window but I can't tell in the pictures. Thoughts? Thanks in advance.