Galanter, of Miami, is due to testify Friday. He has declined comment ahead of that appearance.
"He was my guy," Simpson said of his long friendship and professional relationship with Galanter.
He said Galanter told him he was within his legal rights to take back possessions as long as there was no violence or trespassing.
Grasso has said it was Galanter who convinced Simpson not to testify.
While the trial prosecutor testified earlier that there were preliminary discussions with Galanter about a plea bargain, Simpson testified he was never told a bargain was under consideration and that he did not remember any offer being given to him at trial.
Asked by Palm if he knew he could have gotten as little as 30 months in prison if he pleaded guilty to robbery, Simpson said no, and that he would have considered it if he had known.
Simpson also said Galanter led him to believe he could not be convicted on the charges.
"If you understood you could be convicted on the state's evidence, would you have testified?" Palm asked.
Simpson said yes.
Dressed in a drab blue prison uniform, Simpson spoke clearly as he recounted events leading to the hotel room where the dealers had the memorabilia. His voice cracked a bit as he told of recognizing items on the bed, including framed photos that used to hang on the wall of his Los Angeles home.
"Look at this stuff. Some of the stuff I didn't really realize was gone. These were things I hadn't seen in 10 years," he said. "You know, you get a little emotional about it."
There is no jury in the hearing and Simpson's fate will be determined by District Judge Linda Marie Bell. It remained unclear Wednesday whether the judge plans to make an immediate ruling or issue a written order later.
While Simpson's previous court cases were media events, including his 1995 acquittal in the Los Angeles killings of his ex-wife and her friend, there were empty seats in the Las Vegas courtroom for the first two days of the hearing.
But on Wednesday, the courtroom was full, with Simpson family members and friends in the second row. A marshal turned people away, sending them to an overflow room where video was streamed live.
Still, the scene was much tamer than in the past.
"This is less hoopla than I expected. It's real toned down," said Wyatt Skaggs, a retired defense attorney visiting from Laramie, Wyo.
Find Ken Ritter on Twitter: http://twitter.com/krttr