LONDON — What appeared to be an open-and-shut case involving a jogger in London who pushed a woman in front of a bus is suddenly — and surprisingly — open again.

The police this week shared a video of the May 5 incident on Putney Bridge, which resulted in the woman’s tumbling into a traffic lane and nearly being hit by a bus, and they asked the public to help identify the man who pushed her.

On Thursday, the case appeared to have been cracked: A man was arrested on suspicion of causing grievous bodily harm.

But on Friday, a London law firm said that it was representing the man who had been arrested — a 41-year-old American private-equity executive who lives in London — and that he was innocent.