The hole was underneath some material and that Soyuz has only been up there since June. Sure, an astronaut could have done it but they typically aren't working

The hole was underneath some material and that Soyuz has only been up there since June. Sure, an astronaut could have done it but they typically aren't working on the Soyuz because it's not really something you have to maintain since they are constantly sending up new ones. It's much more likely the mistake was made on the ground. Soyuz is made by Energia, a partially Russian state-owned company that manufactures in Russia.