Agree with this. The ref was looking straight at it and didn't give it.
Why?
Because in the context of a match he might be trying to let the game flow, probably he'd let a foul on a Palace player go 30 seconds earlier, like refs do all the time.
But because it's a penalty against them, play gets rewound for as long as it takes to find something to rule it out, and of course rescind the yellow against St Virgil.
It's utter bollocks, only happens for them, and is totally corrupt.