That's not what it said. You have to be deliberately doing this now. I know you are more intellectually honest than this.No, it does not imply that at all. The "at least" is giving Rush some benefit of the doubt that it was said during his disck jockey days. As in...
At least, the latter was said during his disk jockey days.
The source is clearly the Newsweek article. If they felt a need to make that exception for the first they would have done so. Rush does not claim in the Newsweek article that the first was said during his disk jockey days. Instead his excuse for that one is that his intent was not racist.
"The latter, at least, occurred..." blah, blah. They do not cite when the first did, other than he acknowledged it then began reminiscing about the times as an insult jock. The "at least" is saying that that one "at the least" occurred during that, but then they never cite when the first was made, because they simply don't know.