I would be worried about the union flag on the hedge, if I was of some other ethnicity and thought they were having a go at me.
It has reminded me of summat that happened to my friend just after 9/11. Her husband was originally Turkish and they therefore had a Muslim name, though neither of them were interested in any religion. This is Australia by the way. One day she found rancid pork fat in her letter box (ie an outside letter box at the end of their drive). The next day pig's entrails were on her drive. She went to the police and they immediately classified it as a hate crime.
They soon found the culprit - her rather nasty next door neighbour. The officers gave the old cow a police caution: this means the old woman has to stand up in front of the policeman while he tells her off and warns her off. I've seen a caution being given - they can be quite scary. She left my friend alone after that - not a peep.
I was thinking, draping Australian flags all over the dividing fence could have been a similar sort of thing, except bits of old pig are cheaper.