user: Walker was challenged in the box by Kieran Tierney and Brown said: "It was a dive. Cheat. What else can you say?"
The Hearts midfielder said: "I knocked the ball on and I've seen him [Tierney] coming out the corner of my eye and felt contact so I went down.
"At the end of the day, I am not the referee. I don't give the decisions."
Brown praised Hearts for their performance, but added: "There is no place in football for cheats and that's been a couple of times here now."
Brendan Rodgers, taking charge of his first Scottish Premiership game, praised his Celtic players' mentality to recover from referee John Beaton's "mistake".
Celtic led via James Forrest's opener but Walker levelled from the disputed penalty.
Walker slammed in the penalty but Scott Sinclair's late winner secured three points for the reigning champions.
"It was a dubious penalty, that was clear. In fairness to the referee, he said he made a mistake," Rodgers said.
"At least he was big enough to admit that.
"We had to show mentality and character in the second half. We were super offensive in the last 20 minutes and eventually got the breakthrough."
Rodgers was understandably delighted with the impact of Sinclair, who came off the bench after an hour to make his debut after completing a £3.5m move from Aston Villa.
"He showed typical hunger and desire to score the goal, with the speed he has shown to get into the box," Rodgers told BBC Scotland after his first league match in charge of Celtic.
"It was wonderful play from Leigh Griffiths and Scott showed a great touch and composure to score.
"He has made a big choice to come here but I am sure he will do well and score many more goals.
"He is a really top talent. It has been a bit difficult for him the last couple of seasons at Manchester City and Aston Villa but he brings excitement - he gets you off your feet with his pace and trickery, and he loves scoring goals."
It completed a whirlwind 48 hours for Sinclair, who only arrived in Scotland on Friday night, and completed the final details of his transfer late on Saturday.
"It all happened so fast," he told BBC Scotland.  "I only had three hours' sleep on Friday, but I did the scans and bits and pieces yesterday and I made the squad.
"It is an amazing feeling to come on and score the winner. I didn't think I would be involved but the manager said I was fit.
"This is why I came to Celtic - to play games, score goals and start enjoying it again. Hopefully it can continue."
Rodgers admitted he wants to add "at least another two" players to his squad before the transfer window closes.
One of his new signings, Kolo Toure, was struggling with a groin problem late on, in his first start for the club.
"He wanted to continue," Rodgers added. "I thought he was excellent. He is still a way off with his fitness but he showed he can still play in these big games."
Hearts head coach Robbie Neilson felt his side could have had a second penalty when Toure clashed with Robbie Muirhead.
"There were a lot of inconsistent decisions today," he said. "We got some, they got some.
"In my opinion Toure leans into the back of him. If there's no contact on the ball and the boy goes down it's a penalty."
The Tynecastle boss also revealed he hopes to make at least two signings before the end of the transfer window.
"We're still looking to get a couple of guys in," said Neilson. "[Krystian] Nowak the centre back came in last week so we'll hopefully get that tied up in the next couple of days, and we're also looking for a wide player."
What is a summary of this text?


assistant: Celtic captain Scott Brown described Jamie Walker as a "cheat" after the latter won a penalty in Hearts' 2-1 defeat at Tynecastle.