Outdoor camera siren doesn't turn off when the alarm system is disabled

Wanted to get a second opinion

I called in to let the know when I don't turn off the alarm in time (My app hasn't been working or refreshing right and the alarm goes off more) and I do disable the alarm,  then the camera outside goes off  for 20+ seconds or minutes after. 

He told met the alarm was designed to go off for 6 minutes after it goes off.

But this seems like a design flaw. 

I reiterated that even when the alarm is disabled by me or others,  it still goes off.