Did him no service - Idioms by The Free Dictionary
do (one) no service (redirected from did him no service)
do (one) no service
To do something that hinders or is detrimental for one. You do your kids no service by catering to their every whim.
do somebody a/no ˈservice (formal) do something that is helpful/not helpful to somebody: She was doing herself no service by remaining silent.