He's referring to Tim Morrison, who actually confirmed the quid pro quo, but said he didn't believe what happened was illegal.
"Taylor testified that Morrison told him Sondland had demanded the Ukrainian president announce an investigation into Burisma,
while Morrison said he remembered Sondland saying an announcement by the country's top prosecutor would suffice. Taylor also indicated Morrison met with the Ukrainian national security adviser in his hotel room, while Morrison said it was in the hotel's business center.
Morrison said he learned about a delay in military aid to Ukraine shortly after assuming his post, and was tasked with coordinating with various agencies to demonstrate why the aid was needed.
"I was confident that our national security principals — the Secretaries of State and Defense, the Director of the Central Intelligence Agency, and the head of the National Security Council — could convince President Trump to release the aid," he said.
Morrison testified he had "no reason to believe" the Ukrainians knew of a delay in military aid until August 28, and said he was unaware the aid may have been tied to the demand for an investigation into Burisma until he spoke to Sondland on September 1."
https://www.cbsnews.com/news/tim-morrison-testimony-read-the-full-text-of-white-house-officials-opening-statement-to-impeachment-committees-today/