The armed father has very little trouble breaking into Inspector Kobick's office in the midst of SID Headquarters. However, this might be a ploy by Kobick to get the Earthlings to volunteer their services without his rewarding them their freedom.
Kobick tells the 8-10 year old boy, "I'm Inspector Kobick - you know who I am." As a high-ranking officer in what is essentially the secret police, how likely is it that Kobick is publicly known, much less to a child that age? (It's possible he is a famous J. Edgar Hoover-like figure, although there are very few indications of this otherwise.)
This episode raises the question of how much the Earthlings weigh. Presumably Dan and Steve weigh roughly 200 pounds each: wouldn't that be enough to set off cave-ins? The impression here is that they weigh very little.