The person recovering from a stumble needs a path onward, not repeated reassurance about the stumble.

Kindness aimed backwards can keep someone standing in the wrong place. Repeating that it was fine, that nobody noticed, that it did not matter, returns the person to the moment again and again, when what they need is somewhere to put their attention next. Reassurance is comforting once. After that, it becomes a way of holding the event open.

If someone near you has slipped, say one warm sentence and then hand them the next thing: a task, a question, a plan for tomorrow. Moving forward together does more for them than another round of telling them it was nothing.