The League Cup brings Crystal Palace fans into contact with opposition supporters that, due to the club's Premier League status, tend not to visit Selhurst Park often. Shrewsbury Town fans were welcome guests last month - they came, sang, watched their team battle bravely and cause Palace a few problems, and left. That should be the norm, win or lose.
The visit from Charlton yesterday was not such a case. Despite the Greenwich club being roundly consigned to third place in the rivalry rankings, it's still a game that is likely to have some flashpoints. Blame often falls on both groups of supporters - there are some who just cherish the aggression that comes with a local derby.
With that in mind, it's unfathomable that, despite a significant police presence prior to kick-off, that presence was then nowhere to be seen after the final whistle. The outcome was entirely predictable and wholly avoidable, with supporters suffering injuries from violence that followed.
It's clear that there were plans put in place to determine how to control supporters pre-and-post match - the police met with the club, supporter representatives and a member of the Football Supporter's Federation - to draw up a gameplan and to explain their intentions. It was made clear that there would be a dispersal order for much of the day to avoid clashes between rival fans. The clashes that followed the full-time whistle clearly showed that these plans were flawed.
What is also clear is that, according to Palace's fan representatives in attendance at the meeting, the possibility of holding supporters of Charlton back for 15-minutes was dismissed. Why was this the case? What prevented the police from enforcing a method that they've used for previous 'high risk' matches? Why do they employ such a method at Millwall and not at Palace?
As is often the case with these incidents, innocent bystanders are very often caught in the middle of such aggressive behaviour. Wednesday's flare-ups saw bottles being thrown, with supporters young and old suffering injuries. These were not your stereotypical football hooligans who got injured.
It's imperative that, for future high risk matches, more is done to ensure that fans don't fall victim to needless violence. It was clear during the match (with video evidence on some forums) that there were supporters looking to cause trouble. Why weren't they removed from the situation before it became a problem?
With Palace being the home side, it would have made sense to police the match in a way that gave preference to Palace's fans. Holding back Charlton's supporters for 15-minutes would not have caused a great deal of inconvenience and would have avoided the aggression that we witnessed at the top of Holmesdale Road and the surrounding streets.
After the excitement and entertainment of a resounding win over Charlton, the aftermath left a bitter taste that could and should have been avoided.