Well, they had to have time to go find his 'second gun' and then take it to the hospital to plant on his gurney.
REMEMBER, the second gun wasn't found outside of COSTCO.
It was found by some EMT or Hospital staff on his gurney after he got to the hospital.
I would bet that the second gun was a cop throw down as Scott had a license for every gun that he owned. But golly, not the “hidden” gun found by an EMT! And that odd? (a little snark there)