Treimanis explains his unusual gesture

Latvian Andris Treimanis recently refereed a friendly match between Riga FC and RFS, played Estonia because in Latvia it was still not allowed. At 75' RFS player Kouadio showed his middle finger to an opponent. Treimanis spotted it and sent him off. However, the red card was followed by a very unusual gesture of the referee, who showed his middle finger to the offender.
There was some confusion and Treimanis explained in a video that he did not insult the player, but he only replicated the player's gesture to make it clear why he was sending him off.