Error code BSOD - 0x00000000c0000005
Error code BSOD - 0x00000000c0000005
There's no such thing a flying colors, a pass just means that Memtest was unable to find a/the problem. No memory tester is perfect, so at best all you can say is that the RAM seems to be OK.
It's always a worry when users present with problems that look like bad RAM and their RAM isn't on the QVL. I'm not saying this is a cause but I can't rule it out either.
Similarly, installing RAM without checking compatible slot setups and/or requiring the initial RAM to be inserted into a designated slot first may lead to issues. Products and methods evolve, and those who assemble systems without reviewing the manual face potential problems. This approach is not covered by warranty.