The lines between work and personal life are blurring at such a rate that it is not surprising to me that people will use work resources as if they are at home. I for instance am writing you from work. I spend most of my waking life here. It is the same for many, many people. In my humble opinion, I think that some folks get lulled into a sense of dangerous complacency much as animal trainers do with their animals, or drivers, etc. We are the worst judges of our weaknesses or faults.
If you are around something too long without incident, you begin to take it for granted that it is safer than it really is.