Police responded to reports of a burglary at the house in Vohburg an der Donau near Ingolstadt after the 31-year-old's son jumped out the window and ran to the neighbour's house because he was worried about a burglar.
The 12 year old was home sick and his mother was away for 10 minutes, the Süddeutsche Zeitung reported.
Four police cars responded to the call.
As a result, despite the resident's protests and insistence that no one was in the home other than those that were supposed to be, police insisted they ensure the house was clear, the chief police inspector told the Regensburg court on Wednesday.
It was during this sweep through the house, that police discovered the cannabis plantation.
The house had been under suspicion before, as an anonymous letter sent to police claimed that the resident was a drug dealer.
The letter said that she owned a Mercedes despite being unemployed.
Neither the woman nor her boyfriend, who rent the house, could be charged in the case as police could not determine who owned the plants, which were destroyed after being discovered.