In my previous company, we experienced a reoccurring nightmare. It went something like this: New critical bug arrived from QA: Program suddenly crashed. Reproduces 1 / 10 times. Reproduce steps – unclear. The development team, after realizing they are unable to reproduce the bug on their development machine would claim the bug doesn’t reproduce, moving the ticket back to QA. In return, the QA team reproduced the bug, moving the ticket back to dev.