AFM"Nessie Inc" example question of valuation of Type 3 acquisition (BPP Text)!

Dear our friends, I have done the example of valuation of Type 3 acquisition ("Nessie Inc") in BPP Text book (page 327, 328 with version 2015-2016). In this question, they said that all old debt's interest of Nessie (the acquirer) would be reduced from 7.5%s to 7%. Post-tax projected CFs of Nessie in future are provided. The problem is: if the interest rate reduced, then IMO there was tax effect on the post tax operating CFs as follows: + Pre-acquire: Operation CF post tax = EBIT - Tax (pre) + Post-acquire: Operation CF post tax = EBIT - Tax (post) (tax(post) = tax(pre) + reduction in interest x tax rate). + Therefore, Pre-acquire CF = Post-acquire CF - reduction in interest x tax rate. But in the solution, they just combined the operating CFs (post-tax) of Nessie and Patsy (company to be purchased). Is it actually correct? Rgds,