[Pierre-Marie Baty]

why so complicated, guys ?

// is enemy looking at more than 90° aside of the bot's forward direction ?
if (fabs (WrapAngle (pEnemyEdict->v.v_angle.y - pBotEdict->v.v_angle.y)) > 90)
{
   // yes, it is (meaning, bot sees the back of its enemy)
}
else
{
   // no, it is not (enemy is facing the bot)
}