Yep. I witnessed a classic example of where it could all go bad.
I was at the Airfield and when I am prepping etc, I turn my hand held on and listen to the radio while I am getting ready. Now I knew there was a bird in the circuit because I watched him go up and I could hear him. Now he assumed as there was nobody else around, he wouldn't bother making calls while he bashed a few circuits. Then.... I heard the distinct sound of a 2nd aircraft. He, probably thought, because he could not hear any calls, there was nobody around, so he just blasted right over the AD (and through the circuit).
When the other guy came down, he was furious the 2nd guy didn't make an inbound call, to which I stated, "if you were calling your corners, I bet he would have"
Both assumed as there was silence, there was nobody else around. It is dangerous to assume.