Jeepers that's crap advice. Remembering back to your previous thread, is this the same accountant who told your friend they'd be better off dealing with Revenue themselves?! Probably good advice given how incompetent the agent seems to be.
Simple answer is this, if your friend is satisfied their income tax liability (other than PAYE deducted at source) for 2015 will be nil then they needn't pay any preliminary tax. This is regardless of whether there's a liability for 2014...
The reason being the prelim tax requirement is the lesser of:
100% of the previous year's (2014) liability, and 90% of the current year's liability (2015). So obviously, 90% of zero is zero.