Well did Ash mention about seeing Lucario previously.
The reason why i think Electabuzz was acting that way was i think because it was afraid of Reiji. Also the way Paul defeated Lucario, i think he might make a mental note that Lucario is a weak pokemon. If this is true, then the chance of Ash getting a Lucario will increase more.
Also when Jessie tried to lure Lucario with a chocolate bar it kind off reminded me of the movie where Max tried to cheer Lucario with Chocolate & at the end Aaron & Lucario sharing a Chocolate in the credits.