I suppose that logically speaking, if I know that most cops have a blank loaded as their first shot, logically, I shouldn't be startled by the first shot. But that said, an encounter like that is so traumatic, to both the officer and the suspect, that I hardly think any one in that situation is thinking very logically at the time of the encounter.

I think the issue being raised here is rifles that make use of the pressurised gas produced by the bullet leaving the rifle... as there is nothing to retain the pressure it will not load the next.. Which is why they have 'Blank Firing Adapters' to create the pressure: https://en.wikipedia.org/wiki/Blank-firing_adaptor