I'm going to suggest human error. There's no good reason for something which amounts to an international embarrassment, including putting cosmonaut's lives at risk.
Also note how quiet Russia is about it.
Also note how quiet Russia is about it.
For a direct example have a look at Litvinienko poisoning or skripal attacks.
This behaviour from Russia will not stop.
Please clarify.
If the US wanted to have the moral high ground on this issue they shouldn't have done it themselves. This goes for a lot of things where the US had a 'first', and which other countries then more or less out of necessity follow.
In 1985. The US has tested antisat weapons since, yes, but not in this reckless fashion.