You think that danger declines when kids are present? You underestimate the world.
I agree he basically says let me do my job, but after the fact.
He should have stated there was a complaint and ask if the weapons were real and then if he felt it was necessary ask if he could confirm that.
If he felt he had probable cause he should have explained what he was doing and not just wandered over.
If he felt there was a danger he should have watched and waited for a second officer and then told people he needed to examine the weapons to confirm they were not 'real' and asked them to stay back while he did so.