This issue has not been yet been resolved. Running a ClickEvent via a /tellraw command from a command block still produces output to the player. This may be a feature rather than a bug, but it certainly would seem that a command block should not output messages to the player's screen if the appropriate gamerule is set as such.
This issue should probably be reopened, as there is no good way to test for ranges of a mob's health. /testfor HealF and MaxHealth are capable of finding specific healths, but map-creators cannot realistically track if mob with 100 health has more than 20 health.
MC-64171
This issue has not been yet been resolved. Running a ClickEvent via a /tellraw command from a command block still produces output to the player. This may be a feature rather than a bug, but it certainly would seem that a command block should not output messages to the player's screen if the appropriate gamerule is set as such.
This issue still persists in 1.7.2.
Confirmed for snpshot 13w48b.
Bug still exists in 14w11b.
This issue should probably be reopened, as there is no good way to test for ranges of a mob's health. /testfor HealF and MaxHealth are capable of finding specific healths, but map-creators cannot realistically track if mob with 100 health has more than 20 health.