That doesn't really matter. What matters is that he was in Canada at the time.

What's interesting is that India has been claiming the guy is a terrorist for years, but never really gave specific examples of what made him a terrorist other than his spouting separatist beliefs (which maybe is enough in India to arrest someone?)

But they also don't seem to have bothered to even try to extradite him, which seems telling in itself.

Not only that, but Canada has proven its firm hand on this. When China went apeshit after Meng Wanzhou's arrest in Canada to extradite her to the USA, Canada stuck to its guns. Even after two Canadians were taken hostage by the Chinese government in a retaliatory arrest, Meng stayed under arrest with her extradition going forward, while the rest of the world (including Modi's India) politely looked the other way rather than angering China.

India cannot possibly claim they couldn't have gotten results from Canada if they'd gone through the legal system.

And all the Indian news outlets are claiming the guy was a gangster and that this was a gang-related shooting. Meanwhile the local Winnipeg police are just like "Uh, we have no evidence on that as of yet and have made no statements about that, where the frick are you getting this claim from?"

Oh no, its a clear reference to the blind eye the west & the world has turned to the ongoing genocide of Muslims & Christians in India by Modi govt & the Hindu supremacist thugs it supports.

If the west is scared of China, then India's PM Modi is terrified of them. In June 2020, When China invaded India in Galwan and beat our 20 soldiers to death, Modi publicly state that nothing happened in Galwan. Since then he has been unable to take China's name, even when China built an entire village with paved roads in the Indian state of Arunachal Pradesh.
The Modi govt that rules India is ideologically fascist dictatorial, majoritarian, and violently Hindu supremacist. If that is also your country's ideological stance then we do have a lot in common.

So what will providing proof accomplish anyway?

I don't agree. Something is better than nothing, even if things are heavily redacted. I as a common man may not interprete them adequately but there are people who can. Especially people from the intelligece community can check and somewhat verify if there is anything plausible with respect to the accusitions. This important for the allies of the Canada too. Canada is a member five eyes, so they can definitely validate their gathered intels with the likes of UK, US if the evidence deemed unfit for public release. So far I have not seen any of those countries conclusively made statements that they validated Canada's allegations. The investigation is ongoing anyway.

It does not matter whether Indian PM admits it or not if evidence is there and the international community verified and largely accepts it as truth. So far I haven't seen this happen.

Off course Canada can do whatever they choose in their jurisdiction. For example, many countries creates travel advisory for their citizens regarding which countries are deemed safe / not safe for them to travel to. If country X says that country Y is unsafe for their citizens to travel to, it's perfectly fine. However, that doesn't mean country Y is universally unsafe. But, when it comes to international relations we can't just hurl allegation to another sovereign country without any evidence, independent verification / backing. Because tomorrow country Z can allege something outrageous about country A without evidence, will the international community accept that without questions as well?

Personally I feel diplomacy from both sides have failed us. It's their job to handle these things more gracefully.