The criticism of the UK police arresting people for social media posts is largely fabricated as the actual arrests have been for people inciting violence/riots and pushing complete falsehoods to promote riots etc.

This incident, however, is completely about politically disagreeing with social media posts which is absolutely not a thing in the UK and would get thrown out of court in a heartbeat if police tried to do that. Also, the police would get heavily sued for wrongful arrest. Also, I can't see that a judge would keep someone incarcerated for that length of time over a social media post in the UK - it's just complete abuse of power.