That is an important thing to note. Most of the telekinetics that Robbie knows wouldn't have to drop the whole shield. "Don't worry - I've got you covered."

Speaking of bowling... his original plan was to bowl them all over with energy balls, but the fact that it might take some time for the shield to go up behind him again overrides that. But without the visible effect, he misses the lowering by about 2 seconds, and one of the recovering baddies takes a hipshot from the floor. The bullet finds Robbie's arm, and there's a sort of screamed grunt.

And then there's a shockwave of blue energy that hurls the liquidators backward into the very solid metal wall, with a collection of soft clangs and thumps. They'll... probably get up later. Gritting his teeth against the pain, Robbie manages to ask, "Anybody want some guns? I know... I'm one short."