A bowl comes to rest and then falls over and touches the jack whilst the next bowl is in course. The Skip moves forward to mark it as a toucher to which the opposing Skip objects. Is the bowl a toucher?
No. For the bowl to be a toucher it must touch the jack before the next bowl is delivered. Law 14.2.1
A bowl, which had been a toucher in the previous end, is delivered with its chalk mark still on the bowl. It does not touch the jack but the chalk mark is not removed. As a result of play, several bowls later this bowl is forced into the ditch within the confines of the rink.
What should happen?
If a player fails to remove a mark from a bowl before delivery and that bowl does not become a toucher, a member of the opposing team or the marker must remove the mark as soon as the bowl comes to rest. Law 15.5
A bowl is dead if, not being a toucher, it comes to rest in the ditch. Law 17.1.1