Not a bad idea. A less problematic approach might be to add a short bit of dialogue to the battledroid when he tells Grievous where the Jedi are. "The Jedi are in hallway 3218, and an unknown droid in hanger bay 5." Something to that effect.
But in all honesty, the first time I watched your clip, I didn't give R2's capture a second thought. It was still a smooth transition without explicitly showing or saying how he was captured. Just my 2 cents though.