The first trial of an alleged client of a Maine fitness instructor who used her Zumba studio as a front for prostitution has ended in an acquittal. Former Kennebunk High School hockey coach Don Hill has said he was engaged in a relationship and never paid for sex. Justice Roland Cole ended Hill’s trial Tuesday after barring prosecutors from entering Alexis Wright’s business ledger into evidence. The trial heated up Tuesday with the defense suggesting the ledger was mishandled as evidence. Deputy District Attorney Justina McGettigan called the assertion ‘‘outrageous.’’ Hill was one of 68 people charged with paying for sex with Wright. At least 58 have pleaded guilty or no contest. Wright pleaded guilty and is serving a 10-month sentence.