IMO the rules are quite clear that chargers under
any circumstances, including changing direction to chase evaders, can only wheel up to 90 degrees and this is at the start of the charge - no other changes of direction no matter how much the player may want one
In your example (which is exactly what happened in a game I played a couple of months ago) the chargers best attempt to catch the evaders is a dismal failure - its just the best they can manage against a slippery enemy. In such cases it is often better for them just to stick to their original charge path in my experience.