The SCJV has no income tax , the income flows to the partners so the tax is calculated at Teck and CF level. They may have different tax rates depending on foreign income components, tax credits available, etc. 
Maybe they will use a theoretical tax provision at the SCJV level? The PEA will be low at SCJV level unless the Liard dividend is shown as coming to SCJV on tax free basis. 
very interesting calculations in deed