Welbeck won a late penalty - via VAR - for Brighton, which was converted by Pascal Gross for their 1-1 draw.
Last season, VAR was hesitant to overturn decisions. However, this year, softer calls have been changed when the referee has consulted the on-pitch monitor. Walton believes that the league has lowered the bar to overturn decisions, as evidenced by Brighton's penalty.
“He's taken the context of the challenge out of it and seen it in slow motion," Walton told BT Sport. “He's seen there's contact - which we can all see - and has judged it just on that.
“The high bar the Premier League uses to intervene has been lowered in recent weeks. It certainly does to me (feels like the bar has been lowered). I've got to re-calibrate my thinking as well.
“If you remember VAR was brought in for clear and obvious errors. Just because there's contact doesn't mean it's a foul - the game is a physical game.
“If we put it in slow-motion, yes, there's clear contact there and you can give a penalty based on that. The point I'm trying to make here is that should VAR have got involved? Or should we leave it to the on-field referee to make that decision?
“There are people out there who would say it's not a penalty, and a lot of people out there who say it wasn't a penalty, so it's not clear and obvious. I do think that bar - as we've mentioned before - has been lowered by the Premier League."