Galliano blamed his memory lapse on his "triple addiction."
"I have a triple addiction. I'm a recovering alcoholic and a recovering addict," he said when asked why his memory was blank. He said he started drinking in 2007 and became addicted to alcohol, barbiturates and sleeping pills.
Though he doesn't remember, Galliano did apologize for hurling anti-Semitic insults in a separate incident captured on video.
After the 45-second footage was played in court, Galliano said these are not his views.
"In the video, I see someone who needs help, who's vulnerable. It's the shell of John Galliano. I see someone who's been pushed to the edge."
The British designer is accused of using anti-Semitic slurs during an outburst at a Paris café in February. French law prohibits public insults based on race or religion. The incident shocked the fashion world and cost Galliano his job at the renowned French high-fashion house after a 14-year tenure.
The 50-year-old designer could face up to six months in prison and more than $32,000 in fines.
The verdict in the one-day trial is expected at a later date.
The Associated Press contributed to this report.