Summary
The man command gives inconsistent results. man tail produces an error: man: command not found.
Typing in gibberish as an argument to the man command gives a more accurate error such as: No manual entry for lksjdflkjsdf.
The man page for tail does seem to exist, e.g. running man -k last lines shows tail in the list of relevant man pages.
It's unclear what kind of parsing is occurring that leads to the man: command not found error.