The people who answer the phone are like a human FAQ system - they're not experts, but just have a database to refer to. Therefore, their information is good if they happen to look up the correct keywords, but they can 'miss'.
Here are the full official instructions about qualifying for Permanent Residence.
http://www.immigration.govt.nz/opsmanual/30505.htm Notice, you MUST comply with RV2.5, and ALSO with any one of the five sub-sections below. You will have to meet the INZ requirement in relation to tax residence, if that is the sub-section you are choosing, regardless of what the Inland Revenue site says, which also applies.