this happened to my eldest yesterday (secondary school) and she lost a pen and pencil as a result. Fortunately they were very cheap items. Hers was not the only bag thrown out and a blazer was also thrown out. Several others were thrown around the classroom but stayed inside. Teacher went into classroom (lunchtime) and sent all the children outside but I suspect they didn't realise about the bags/blazer. My inclination is not to say anything as it may make things worse - what would you do?