I've never seen or heard of that in the UK: if the green man shows, no vehicle can cross the path. It's quite common for traffic to be moving while some part of the crossing is green, but they wouldn't be allowed to use that lane. Indeed, pedestrians will regularly cross at red man - that's allowed, and people know they need to look out in all directions.

All-red phases are a slightly different issue, and indeed, not all crossings have them