Can the referee change a restart if I point out a mistake after play has restarted?

No for the restart itself. Law 5 says the referee may not change a restart decision on realising that it is incorrect, or on the advice of another match official, once play has restarted (or the referee has signalled the end of a half and left the field of play).

Example from the Laws: a defender strikes an attacker inside the penalty area while the ball is in play, the assistant referee indicates the offence but the referee does not see it, and play continues until a throw-in restart. The referee may not change the restart and may not award a penalty kick, but may still issue a red card for violent conduct because the assistant referee had identified and attempted to communicate the offence before play restarted.

Source: IFAB Laws of the Game 2026/27, Law 5 (The Referee): https://www.theifab.com/laws/latest/the-referee/