I'm not sure if you can bind the selection value to a boolean property, but you could add a listener to the Grid to update the checkboxes based on the boolean condition.
grid.addBeforeShowHandler(BeforeShowEvent event) {
@Override
public void onBeforeShow(BeforeShowEvent event) {
List<IncidentDto> itemsToSelect = new ArrayList<IncidentDto>();
for (IncidentDto incident : store.getAll()) {
if (incident.getBooleanProperty()) { //whatever your property is called
itemsToSelect.add(incident);
}
}
isIncidentCM.setSelection(itemsToSelect);
}
}
There may be other implications in using a BeforeShowEvent depending on how/when you populate your store, render the grid, etc. but assuming your store is fully loaded and the property available from your store objects I believe this should accomplish your goal.