Britney Spears ’ reps have shut down “ridiculous” reports that the singer behaved erratically with a knife in a restaurant, and the pop star has also broken her silence since her DUI arrest and subsequent stay in a rehab facility. READ MORE: ‘Controlling Britney Spears’  review: toxic conservatorship back under the microscope Reports about the singer behaving erratically in a restaurant emerged on social media earlier this week, when one person claimed that they were seated near her in a restaurant and saw her acting in a way that meant “one diner feared for her life”. They described it as an “INSANE dining experience” and added that it was “not a joke”, and TMZ later ran a story about the alleged incident, writing that the ‘Toxic’ singer was allegedly “screaming “ and “barking” while at the Blue Dog Tavern in Sherman Oaks, California, and also walked past a table with a knife in her hand.…