Touch screens can be... touchy! If you want to confirm every move you make, you can enable Confirm Each Move in your settings!
Tap More in the bottom menu and select Settings
Choose Play from the Settings menu and tap Live Games
Toggle the Confirm Each Move option and then every move you play in your live games will offer a checkbox to confirm before the move is played!
Be warned, when you are very low on time, this can make it difficult to play quickly!