According to Wikipedia, his statements may have been more a function of the system than his own willingness to outright fabricate material.

https://en.wikipedia.org/wiki/Muhammad_Saeed_al-Sahhaf

His pronouncements included claims that American soldiers were committing suicide “by the hundreds” outside the city, and denial that there were any American tanks in Baghdad, when in fact they were only several hundred meters away from the press conference where he was speaking and the combat sounds of nearing American troops could already be heard in the background.

US intelligence analysts later concluded that Al-Sahhaf confidently made false statements because he genuinely believed in what he was saying. As the American forces approached Baghdad, the Iraqi army falsely reported that they had successfully counterattacked US forces, destroying numerous tanks and killing hundreds of American troops. Army Col. Steve Boltz, the deputy chief of intelligence for V Corps, expressed that they held the belief that Al-Sahhaf sincerely held the information he reported to be true. Boltz theorized that because Saddam’s regime was known for frequently punishing those who delivered bad news, military officers would fabricate reports about the battlefield situation. This systemic self-deception within the Iraqi hierarchy led to a surprising lack of awareness when the Americans entered the capital, with some captured Iraqi officers later bewilderingly admitting that they had no idea that the US forces had been so close.