It's not clear how far any memorial services were actually disrupted by the demonstrators. If they were, I can't condone it, and I think the law should be able to do something about it. But in any event, that's not what Choudhury was charged with.
I'm against this law if it's going to be interpreted in such a manner. Burning the poppies to make a political or religious point, presumably about colonial imperialism or some such thing, seems to me to be something that should be permitted. I'd say the same about burning a flag at an anti-war rally. These are not my preferred ways to make a point, but people should be politically entitled to express their point, and their emotions, in a vivid and highly provocative way. Emotional upset from something like this should not count as "distress" for legal purposes.
Likewise, I should be permitted by the law to organise an anti-Islam rally and burn a Koran or an effigy of Muhammad at it. It's not my preferred way for someone to express opposition to Islam, but that doesn't mean it should be illegal. But if I lead such a rally, I shouldn't get to lead my marchers into a mosque and disrupt whatever peaceful activities are going on there.
Before someone asks me where I draw the line, I don't think there's a clear line that must be drawn here or here. It's a matter of judgment, with different values to be weighed up. I think the state needs some reasonable discretion as to where it draws its own line to protect events from disruption (and to deter provocations to violence and the like). There may be various policy considerations and they may vary from case to case.
But I do think that burning the artificial poppies should have been legal in this instance, and on the sketchy facts in the report Mr Choudhury shouldn’t have been convicted of a crime.
We ought to be consistent about this. If we want robust protection of freedom of speech, that will also apply to ugly forms of speech and/or to the speech of our opponents.