Every country uses a combination of older and newer equipment in any war. The war propaganda wizards just try to make things like that look unique to Russia.
Why in God's name would you use a 6-bit signed integer for anything on a spacecraft? I know space-certified chips are pretty barebones, but surely not that bare bones...
The tweet you link didn't indicate that. It said that an engine failure likely caused the overrun, running for 127 seconds instead of the planned 84. Why would something have a 2^7 int size check?
Edit:
Quoted
The head of Roscosmos Yuri Borisov said that the main cause of the #Luna25 crash was an engine failure. Instead of the planned 84 seconds, he worked 127 seconds.
Mistakes happen. For example, may I introduce you to NASA's 125 million dollar Mars Climate Orbiter, which spent most of a year traveling to the Red Planet before ignominiously burning up because a Lockheed Martin programmer decided to write the thruster-firing calculations in Imperial units (feet and pounds) instead of following the specifications to use metric units (meters and kilograms).