Answered May 1st, 2019

Rajon Rondo has 23 assists, posting the 1st 20-assist game vs the Spurs in the Popovich era, which began in 1996.

Who was the first NBA player with 20 assists in a game against the Spurs after 1996?
Interpreted as:
Who was the first NBA player with 20 or more assists in a game against the Spurs after 1996?