This is a really simple concept. Stuff goes wrong. Someone made a mistake. Things break. Features end up taking way longer then expected. All of this will blow your schedules to pieces. You get angry: how can anyone be this stupid?
Get back into your seat hothead: no one with a clear mind sets out to break things, not meet the schedule or ship an incomplete feature.
There is always something to learn and to teach, but assume good intent. Make sure to inspect your process, start with why and over-communicate. Understand before being understood. Try again.