Fibre optic cable does not need to be grounded. However Fibe is not always fibre optic. If the Bell cable has copper conductors it is not fibre optic and needs to be grounded.
In any event, the installer was unprofessional and negligent. What he did could cause damage to the Bell cable, is unsightly and could cause extra installation charges if Bell services are installed in future. The Bell cable should have been left in place. He probably didn't want to drill another hole. I would call Rogers, register a complaint, ask that the Bell cable installation be restored to it's original condition and the Rogers installation redone.