Have blameless conversations
In DevOps, if you have an outage, you’re supposed to have a blameless retrospective. This principle can be generalised beyond DevOps: when we work together, things invariably go wrong sooner or later. When they do, you should have a conversation without blame, reminding yourself that the other person is no less competent than you, and try to understand what happened. Maybe you were missing some factors that went into the decision. Or what you thought is the right course of action may actually be the wrong one. So have a blameless conversation. Start with the assumption that the other side knows what they’re doing and seek to learn, not with the assumption that they don’t know what they’re doing and seeking to blame. If after an open-minded conversation, you feel blame is justified, you can blame him, but not to begin with.