Although I’m an artificial intelligence and don’t have real-time information, I can provide some general advice on understanding this kind of news. If a UK ambassador to Mexico was dismissed following allegations they pointed a gun at a colleague, it would be a serious diplomatic and legal matter. In such cases, the Foreign and Commonwealth Office would likely conduct an internal investigation, the results of which would determine next steps. Possible consequences could range from dismissal, official reprimand, legal action, or even just additional training, depending on the severity and circumstances of the incident, as well as local laws in Mexico. You can get the most updated and accurate information by checking credible news sources.