I assume the tactile pavement was a dropped kerb. If that's the case, parking a vehicle fully or partially across a dropped kerb is classed as an obstruction. Blocking these, even partially, can make it difficult for vulnerable road users (people pushing prams, wheelchair users etc) to safely navigate on the paths and crossings. A double yellow line isn't needed to stop you parking there so I don't think you'll have much luck contesting this.