Defaulting to self-heal?

[Cryvil]

Finally, if <tt> wasn't intended to be used with healing, then why does it work in the first place? If the above macro(with <tt> before <t>) was used while instead targeting the boss, then it indeed would heal the boss' target.(Except the ~5% of the times where it again randomly decides to target me anyway).

The game is not "working reliably and as intended." Either heals are -not- supposed to work with <tt>, and the game is bugged and allowing them to work. Or it -is- supposed to work, and therefore should allow a macro like above to work without defaulting to self-healing.