'Teaching a class at' and 'receiving a degree from' an institution are two very different things. Not sure what these links are trying to prove or disprove?
If Craig Wright has a PhD you should be able to find his dissertation, look up his advisor/thesis committee, see his publications in CS conferences, etc.
Wright, C. (2017). The quantification of information systems risk: A look at quantitative responses to information security issues Australia: Charles Sturt University
Well if he submitted his thesis in 2017, he probably didn't have a PhD in 2015. Also there are several steps between submitting your thesis and getting your degree.
I suspect he may very well have considered himself 'basically done' with his PhD several years ago and just started using the title. He wouldn't be the first
I doubt most schools would hire a teacher unless at minimum they are pursuing a master's/doctoral if they don't have one.
"Many 2-year community colleges often hire instructors with only master’s degrees, as long as they have some teaching experience. Four-year colleges and universities usually require a doctoral degree, unless you have decades of experience in your field, in addition to a master’s." http://www.teachingdegree.org/types-of-teachers/higher-educa...