Hey so I am relatively new to the game and often make the mistake of accidentally reinforcing people I am farming and then not realizing it until way after the recall option goes off.
Now one simple solution for me would be to pay more attention and I will do that.
However, my suggestion is that the sending troops window is changed so that no option is selected. This way I cannot accidentally send reinforcements because I can't send any troops at all until I select whether or not to reinforce, attack, raid, etc.
Does this make sense?