Not software, but I supervised QC inspectors at a medical manufacturer. R&D engineers would constantly try to steal their time to inspect some pre-production part, when we were trying to supply the $250k+ per day manufacturing floor with production parts that were backordered and running out on the floor (we had horrible issues with supply, but that's another story). Sure, your "brand new" part needs some pre-production inspections, but not right now since that part isn't needed for a few weeks. Once I got it into their heads that if they absolutely needed a part NOW they should come to me (so I can work it into the schedule) they always got their parts on-time from us.

I'm sure this is similar to a software workflow with QA, where every developer is vying for limited QA time, so I don't think "getting furious" is too far a step.