Question on F7 - Tax - So confused!!!!

Hi Sir, The question is from the BPP booklet Q. 139 on page 40. Question: "Isaac & Joseph purchased new machinery on 1 January 20X5 for $1,000,000. It has a residual value of $200,000, with the useful life deemed to be 8 years. The plant is depreciated on a straight line basis. Tax allowances of 50% of the cost of the asset can be claimed in the year of purchase, as depreciation is not allowed for tax purposes. The rate of income tax is 30% Identify whether a deferred tax asset of liability should be recognised at 31 December 20X5 and at what amount?" ANSWER: Tax Liability = $60,000. How is this the case? This answer assumes that we only compare the depreciable value ($800,000 - $100,000 (depreciation)) of the carrying value to the tax base (500,000)? This directly conflicts with the logic used in the below's lecture example? https://opentuition.com/acca/fr/ias-12-example-accelerated-capital-allowances-acca-financial-reporting-fr/ Please help! This has made me so confused as to where I am going wrong!! David