Seeking legal advice post Wembley

As above...got searched on the way in yesterday and was arrested for possession of smoke flare which I had forgotten was in my pocket (the type of which about 30 went off at Covent Garden and at the Watford Semi-final). Silly boy I know, but I'd had a few beers and considering how inconsistent they are with applying this law I think an arrest, missing the game, sitting in a cell for 6 hours and a subsequent court date are a little on the harsh side.

I'd appreciate it if any legal BBS-er can PM me for some advice.