British Cycling and Team Sky's former head of medicine Dr Steve Peters said he felt like he was "being made to solve the crime" as he gave evidence at Dr Richard Freeman's tribunal.
Dr Freeman, the former British Cycling and Team Sky doctor, is facing a hearing at the Medical Practitioners Tribunal Service in Manchester to determine his fitness to practise medicine.
Dr Freeman has already admitted, among other charges, ordering a package of testosterone patches in 2011 and then lying about it, including to Dr Peters.
The General Medical Council, which brought the case, argues that the drug was ordered not, as Dr Freeman contends, to treat former head coach Shane Sutton's secret erectile dysfunction but with the intention of giving it to a rider to enhance performance.
Sutton denied Dr Freeman's version of events in explosive testimony on Tuesday before storming out and refusing to return.
Dr Peters, who worked closely with both men, faced a full day of questioning and remarked seemingly in exasperation: "I feel I'm being made almost to solve the crime. All I am saying is I have a man who has lied to me and another guy who is also untrustworthy."
The Testogel was part of a package, which it was alleged on Thursday also included the erectile dysfunction drug Viagra, addressed to Freeman and delivered to the National Cycling Centre.
Dr Freeman's QC, Mary O'Rourke, put to Dr Peters: "If it was ordered to dope a rider, that's not how you would do it unless you were mad."
Dr Peters agreed and also suggested that an athlete using such a patch would quickly fail a doping test.
"It would be picked up very quickly," he said. "It would be very hard to do this."
Dr Peters added: "What didn't make sense is if someone were to cheat they wouldn't go through the supplier for British Cycling where there's a paper trail. Initially I thought it must be someone forging his (Dr Freeman's) signature."
But, while Dr Peters said the GMC had "made a leap" by claiming the testosterone must have been for an athlete, he also cast serious doubt on Dr Freeman's claim that he did not tell his colleague it was for Sutton because the coach wanted it kept private.
"That doesn't quite add up," said Dr Peters.
"My relationship with Shane was very up and down, as I think with everybody, but Shane is a very open book. Shane came to me many times. I just didn't understand why he would not tell me. He confided a lot in me about his relationships."
Dr Peters added he thought that Dr Freeman may have ordered the patches for himself, using Sutton as a decoy.
Sutton engaged in angry exchanges with O'Rourke on Tuesday and at one point called Dr Freeman, who is being treated as a vulnerable witness and was separated from Sutton by a screen, "spineless".
Dr Freeman was absent from the hearing on Thursday, with O'Rourke saying: "Unfortunately Dr Freeman had an adverse reaction to what happened on Tuesday. Dr Freeman is not in a fit condition to be here today or tomorrow."
Dr Freeman was due to see his psychiatrist on Friday, while O'Rourke indicated there will be a "humdinger of a debate" to come over whether Sutton's evidence should be discarded.
Dr Peters painted a picture of Dr Freeman as a disorganised man who was unable to keep records properly and who found a lot of things hard to cope with, although he said he had not seen evidence of mental illness.
It was revealed that Dr Freeman had previously been diagnosed with bipolar disorder and had been admitted to hospital on several occasions, including in 2011, when he was struggling with the break-up of his marriage.
O'Rourke stated the police were involved and that there was a concern he might take his own life.
Dr Peters said he was "distressed" when Dr Freeman eventually admitted that he had not told the truth, travelling to Dr Peters' house to apologise in person.
"When I was waiting for Richard to arrive I couldn't believe the position I'd been put in because I trusted him," said Dr Peters.
"I was distressed because I wasn't sure how to defend myself. I expected him to be really quite distressed and when he arrived he was really upbeat. He just didn't seem aware of what he'd done and what he was apologising for."
Despite the situation, though, Dr Peters claimed he did not ask Dr Freeman why Sutton had wanted the testosterone.
One moment of contention came when O'Rourke brought up an interview Dr Peters gave to the Sunday Times in 2017 repeating the lies that Dr Freeman had told him.
O'Rourke suggested Dr Freeman did not know about the interview until afterwards, but Dr Peters said: "That's untrue, Richard came and asked me to do it."
He claimed Dr Freeman did not come clean until three months later, adding: "I don't believe for a minute he put me in the fires deliberately. But it doesn't take much to pick a phone up and say, 'I'm sorry'."
Dr Freeman will claim that Sutton bullied him into ordering the drug.
Dr Peters said Dr Freeman had not given that explanation to him but that there was a pattern of complaints against Sutton for bullying and that he had been suspended in 2008 or 2009 before being brought back because of his proven results as a coach.
Dr Peters said Sutton's aggressive behaviour was well known, adding: "Richard and (physio) Phil (Burt) found it very hard to stand up to that, as did many of the athletes."
Burt, who opened the package of Testogel, will give evidence on Friday.