He could have been using the "s" key, or mouse gestures (right click and hold + drag). Both of these shortcut options are customizable.
s key. you can customize this easily
The quickest solution is to press the letter "S" on the keyboard.
You can right click and select customize. Go down the list and select the item you want to add to the shortcuts there and drag them to the small toolbar that appeared when you pressed "S"