Even pet immune PIRs should detect something with this much mass. Unless, of course, if they were installed too high or upside down (which I've seen many, many times). This had to be a really poorly designed or implemented alarm system. I am amazed at how many times I go into a place like this for an evaluation and they have a 60 to 90 second entry delay, and their alarm panel is in plain view. Can anyone say "sledge hammer?" Of course, many older alarm systems are still on dial up lines. Can anyone say "wire cutters?"
I would have to think these guys had some type of inside knowledge, as it appears obvious they aren't exactly world class cat burglars by the fact they hadn't already put the grinder together beforehand.
Don't even get me started on the "safe." This is an insulated "gun safe" with thin sheet steel, likely 12 to 7 gauge, is one-tenth to one-fifth the minimum thickness of the lowest rated real safe. They should have been storing these controlled items in a minimum TL-15 rated safe (I think that may even be a DEA requirement). At the very least, it would have kept them there a heck of a lot longer and burned up a heck of a lot more cutting wheels.
Sorry, I know this isn't the right forum for alarms and physical security. I just get so worked up when I see something like this that could have easily been thwarted by a properly designed and implemented alarm system.
That said, I don't have much negative to say about the camera. They got a good quality, color shot of the perpetrators. You can even tell one of them appears to be African American when he gives us a shot of that plumber's crack. It would have been good to have audio. It's always nice when you hear them call each other by name.