The home side were seeking to build on victories over Hibernian and Hamilton, but in a limp display failed to test Saints goalkeeper Craig Samson until Buaben's late strike and suffered a third home loss of the campaign.
Hall was forced to limp off, replaced by Danny Washbrook, and the home side's chaotic start worsened four minutes later when Rovers scored the first try.
The family brought Piper to the Children's Hospital at the University of Oklahoma Medical Center on Aug. 22 because she was having severe coughing fits at home and then her left leg and entire right side went limp.