Dale said he had two or three uneventful meetings with Williams when he first joined the Melbourne-based drug squad in an attempt to be a "top notch detective".
He said he also bumped into the gangland killer, who was at a South Melbourne cafe with known criminals, while having coffee with his wife.
"It was pretty much just acknowledgement," Dale said of his interaction with Williams on the day.
Dale is facing allegations he lied to the ACC at two hearings related to the 2004 murders of career criminal Terry Hodson and his wife Christine.
He has pleaded not guilty to 12 charges of giving false evidence to the ACC regarding his relationship with Williams.
"The intention was to see if we could get any information ... but it didn't pan out that way so we didn't go any further," he said of the meetings.
Prosecutors say Dale lied to the ACC because he knew he was suspected of involvement in the Hodson murders, after Hodson had agreed to give evidence against him over burglary and drug charges.
Dale described Hodson to the ACC as a "very cunning criminal" but a useful police informant.
He said he was aware that at one stage Hodson was in possession of thousands of ecstasy pills.
But he told the ACC Hodson had been given a green light to sell them, to prevent blowing his cover as a police snitch.
"On our authorisation he was able to deal in numbers that put him in the top echelon of sellers in Melbourne," Dale told the ACC.