There are casualties from some of these IDF bombings, as in one the IDF is investigating now. So even though there are some of these staged events, there are others that are real. What the IDF is saying about this recent one is that Hamas wouldn’t let the people leave as the IDF was about to strike.
Israel is saying that the deaths of the children in the school probably were caused by Hamas bombs that fell short and not by the IDF.
It is true also that Israel is reporting that Hamas kept them inside and would not let them follow Israeli instructions to evacuate.