That's how I saw it.
Lawrence altered the angle of his run to collect McAllister's leg once he knew the ball had gone away from him. Had he run directly to the ball, he wouldn't have run into McAllister. Can't blame him really.
Sadly, The Mike Riley Show was in town and he wasn't allowing any physical contact without blowing his whistle. I'm not suggesting for one second he was biased, as he gave us numerous freekicks for bugger all. He was just incompetent.