Dodge enough bullets (as the crew of Mir did in those days), they may have figured, and it proves you’re bulletproof forever.

The Russians have indeed dodged many bullets, while in space.
But what about their spaceship, the Soyuz? They've learned from their ealier tragedies.
The lessons from Columbia and from Challenger are about the reliability of a spacecraft that goes to space and comes back from space. These are the most dangerous phases of a spaceflight and these phases should condition the choice of spacecraft: make it forgiving, make it tough, capable of withstanding tremendous stresses even if it means disconfort to the crew, don't bother with sophistication, high-tech but with simplicity. Going up and down are only a tiny fraction of the time spent during a mission in space.

The ESA contribution to the Shuttle program is also substantial and I'm sure NASA can't find failures to honor our obligations.
But the ESA lost its first Spacelab module as it was given to the US after its first flight.
In Oberg's 2 part TV documentary (also called Red Star in Orbit?), I remember the flight of Soloviev and Balandin (1989?): at one point they went out to repair loose protections around their Soyuz capsule and when they wanted to return back, they discovered they couldn't shut the hatch as it had been forced earlier. They "rushed" to another hatch and got back in safely, but they had quite an anxious moment: imagine being outside, unable to return back inside the ship!

Raoul