The incident occurred on his home debut in October as Saints lost 2-1 against Tottenham and he was subsequently dropped by then manager Nigel Adkins.
After an internal inquiry the club decided to take no action but Boruc did not regain his place until January.
The Poland international, who joined Saints in late September as a free agent, claims Adkins did not want him in the team and the incident gave the manager the ideal excuse to exclude him.
"I won't say I regret it, because I heard insults from the stands. Racist ones," Boruc said in an interview in Polish newspaper Republic.
"I blamed myself for it because I gave Adkins the reason that he could sit me on the bench.
"One must remember I joined them when not ready, so I had to catch up with the rest.
"The situation was a bit funny. Adkins didn't see me in the team, but his bosses decided to hire a new goalie because the team played poorly.
"I was thinking I'd get ready quickly but I had to come to terms with a different role.
"The coach had his vision and I was a bit angry. The games I played I didn't do too well and there was the incident with the bottle.
"But I like such challenges, and feel good when I hit the bottom, because you can start from scratch."
Boruc's management company declined to respond to the claims while Southampton were unavailable for comment.