Based on the little information available it does highlight an interesting point of intersection between law enforcement and peoples rights. AFAIK, a DV(but does disturbance=violence?) call does meet the standard of exigent circumstances to enter a private property. However, in theory, should a third party's(person who calls it in outside of the home) perception of commotion really over ride the occupants rights? Should LE be required to note some sort of corroborating evidence before exigence is established?
I think that "exigent circumstance" needs/must be re-evaluated on a continuing basis. If they had responded to a DV call and no one responded, then I think you can make a compelling case that exigent circumstances existed that justified making entry without permission or warrant. But once they made contact with the couple inside, I can see no justification for claiming that there was an imminent risk of harm to anyone inside. Best I can tell, they went in because they wanted to go in and wanted to assert situational control and induce compliance. In situations like this, law enforcement and the protection of citizens' rights tend to take a back seat to taking charge of the scene and making those on the scene do what you want them to do.