Dual licensing happens all the time, often with GPL and some other, more restrictive license. He clearly states that until X date, you may only use the code under the Fair Source License. After X date, you may choose which of the two licenses you would like to use.
There's no conflict in adding another license, it's his code, and the license and his directives dictate how people can copy and distribute it. Nor does the fact that there's only one license in LICENSE.txt really mean anything. README.txt is clear about the dual license in its "Licence" section.
There's no conflict in adding another license, it's his code, and the license and his directives dictate how people can copy and distribute it. Nor does the fact that there's only one license in LICENSE.txt really mean anything. README.txt is clear about the dual license in its "Licence" section.