An imposter sparked a security scare at the AFL grand final after jumping the fence to join the post-match celebrations on Saturday. WATCH THE VIDEO ABOVE: Imposter arrested after joining AFL grand final celebrations. The incident has raised questions about MCG security protocols and how the man was able to use another person’s accreditation. Victoria Police said there were more than two dozen evictions at the grand final. “Police maintained a strong presence at the AFL Grand Final on Saturday,” a statement read.