Poor English
Approximately ten years ago, I witnessed the take-off of an Il-76 operating for Heavylift. Turning the radio on, I heared the tower instructing them to turn right imediately after take-off. The reply, in perfect English was: turn right, confirmed, but their turn left in the direction of the only cloud over continental Europe hiding a B-737 on the landing pattern.
This is not he first time that I heard a pilot confirming that he would follow the direction given by the ATC but turns in the opposite direction.
This is not necessarily a language problem.
My twopences worth.
Willy.