I know it is early in the 21st century, but this guy gets vote for dad of the year.

He manages to catch a foul ball while holding his infant son. He also managed not to drop the bottle during feeding time. It should be a cool thing to tell his kid about one day.
I thought the Dodgers announcers were a little harsh about him on the play.
Regardless, from a rules standpoint this one was pretty easy.
Rule 3.16 in the old format:
3.16
When there is spectator interference with any thrown or batted ball, the ball shall be dead at the moment of interference and the umpire shall impose such penalties as in his opinion will nullify the act of interference.
APPROVED RULING: If spectator interference clearly prevents a fielder from catching a fly ball, the umpire shall declare the batter out.
The rule of thumb is if fielder comes into stands, there is no interference. If the spectator reaches across the field, he has done something illegal.
I am actually pretty surprised the umpires did not get this without replay. He clearly reached over into the field. Batter out. Good call in the end.
As a Cubs fan, I can only mumble terrible things about the Dodgers announcers for mentioning the Bartman incident.
Page 65 of RuleGraphics covers spectator interference.