Follow-up/addendum:  I reached out to the Open Zeppelin team And they did not identify any specific deficiencies with the Datamine smart contract (https://forum.openzeppelin.com/t/question-on-smart-contract-inheriting-from-openzeppelin-erc777-implementation/3328/2).  This does not mean that there are no deficiencies, however, it means that whatever deficiencies exist (if any two) are not widely in publicly disclosed.  Despite my profound skepticism for this project, this news is good for them. Now they just need to solve the inflationary mechanism that is built into the project.  Kudos team - your code isn’t overtly fucked.