I lived in NZ for a few months btw and it's certainly included in this, as they're one of the more strict countries for sure.
That said, most countries are never going to do anything so long as you have legit-enough flight details and seem like a decent enough person etc etc. So while this is in no way legal, what I've done very often is go onto kayak.com or whatever and copy/paste an itinerary home to the USA in Word, then add the requisite disclaimers from an older fllight, and printed it out. This certainly meets the "cursory glance" requirement any official has ever had and as I said earlier, unless you seem dodgy no one's going to care beyond this.
Of course, the more legit option is to buy a fully refundable ticket and then just refund it, or buy a cheap budget airline flight elsewhere. In some cases like NZ technically you need proof of a flight home and not just another country, but in actuality so long as you're not showing up clueless that you needed one in the first place no one will care if you have an onward flight even if it's to, say, Oz.
Of course none of this counts as legal advice blah blah blah, just something that may or may not have worked for me.
