Name the impact without exaggerating it
Describe who had to wait, worry, redo work, spend money, or make a choice with incomplete information. For a message about how to congratulate someone on retirement, use this factual base: name the milestone and, when you know it, the effort or meaning behind it.
Make repair practical
Offer the repair you can actually complete, with ownership, timing, and any limit stated honestly. Offer warm recognition and let the recipient decide whether they want a call, visit, gift, or quiet celebration. Make the immediate next step clear enough that the recipient can answer without reconstructing the entire history.
Let future behavior carry the proof
Do not make assumptions about pregnancy, money, relationships, health, or what the achievement should mean next. Follow the person's lead on privacy before sharing their news or photos with anyone else. A promise inside a message is weaker than a visible change in what you do after it.