Another way I would emplement the technique you have illustrated, is to anchor the 1st finger at the 12th fret and hammer-on and pull-off with the right-hand fingers as shown below:
Code:
R1 L1
-14----12------------------------- G string
then
R2 R1 L1
--10-----9-----7------------------ G string
then
R3 R1 L1
--5-----3-----2-------------------- G string
The left/righthand fingers have to hit the string at exactly the same time, in order to pull-off the first note to sound the second note, then to sound the third, so on... You can move up and down the same string instead of moving across the strings. This technique could be more accurate and faster.
L1 = Lefthand 1st finger
R1 = Righthand 1st finger
R2 = Righthand 2nd finger
R3 = Righthand 3rd finger
All the best!