Why? As an element of surprise?
Yes, he did it both times leading 40-0 on serve and was successful on second attempt (Raonic made an error trying to slice). It were two different serves, the first one ridiculous from the level of his breast, the second one typical for this kind of serve - from the knee level on rival's backhand.
Stakhovsky as early as entering the court was in a relaxation mood, he didn't seem to believe in victory from the start.