Yes the Contractor can by all means propose a change to the activity schedule, but not to change the Prices i.e. they can add items to the activity schedule but would have to decrease other activity schedule items to be able to put cost against the new items.
Errors in the activity schedule for items that were in the Works Information under option A are Contractor risk.
Errors in the activity schedule for items that were in the Works Information under option A are Contractor risk.