It's always possible to impersonate police, I'm not sure what your point is? Wearing what the officers in the video are wearing - uniform with a prominent POLI

It's always possible to impersonate police, I'm not sure what your point is? Wearing what the officers in the video are wearing - uniform with a prominent POLICE label - is sufficient to be identifying yourself as police, and would be impersonating a police officer if a member of the public did it.