diff --git a/core/block_svg.js b/core/block_svg.js
index ec1497677..9a7f87596 100644
--- a/core/block_svg.js
+++ b/core/block_svg.js
@@ -533,7 +533,11 @@ Blockly.BlockSvg.prototype.onMouseDown_ = function(e) {
   }
   if (this.isInFlyout) {
     // longStart's simulation of right-clicks for longpresses on touch devices
-    // calls the object's onMouseDown, instead of the flyout's onMouseDown.
+    // calls the onMouseDown_ function defined on the prototype of the object
+    // the was longpressed (in this case, a Blockly.BlockSvg).  In this case
+    // that behaviour is wrong, because Blockly.Flyout.prototype.blockMouseDown
+    // should be called for a mousedown on a block in the flyout, which blocks
+    // execution of the block's onMouseDown_ function.
     if (e.type == 'touchstart' && Blockly.isRightButton(e)) {
       Blockly.Flyout.blockRightClick_(e, this);
       e.stopPropagation();
diff --git a/core/touch.js b/core/touch.js
index 8f06c990f..93587dbc9 100644
--- a/core/touch.js
+++ b/core/touch.js
@@ -187,19 +187,10 @@ Blockly.Touch.shouldHandleEvent = function(e) {
  *     saved identifier.
  */
 Blockly.Touch.checkTouchIdentifier = function(e) {
-  var identifier;
-  // TODO (fenichel): Improve splitEventByTouches to get rid of this try/catch.
-  try {
-    identifier = (e.changedTouches && e.changedTouches.item(0) &&
-        e.changedTouches.item(0).identifier != undefined &&
-        e.changedTouches.item(0).identifier != null) ?
-        e.changedTouches.item(0).identifier : 'mouse';
-  } catch (ex) {
-    identifier = (e.changedTouches && e.changedTouches[0] &&
+  var identifier = (e.changedTouches && e.changedTouches[0] &&
         e.changedTouches[0].identifier != undefined &&
         e.changedTouches[0].identifier != null) ?
         e.changedTouches[0].identifier : 'mouse';
-  }
 
   // if (Blockly.touchIdentifier_ )is insufficient because android touch
   // identifiers may be zero.
diff --git a/core/utils.js b/core/utils.js
index 6886a7d24..e3e392303 100644
--- a/core/utils.js
+++ b/core/utils.js
@@ -96,6 +96,9 @@ Blockly.hasClass_ = function(element, className) {
  * @param {string} name Event name to listen to (e.g. 'mousedown').
  * @param {Object} thisObject The value of 'this' in the function.
  * @param {!Function} func Function to call when event is triggered.
+ * @param {boolean} opt_noCaptureIdentifier True if triggering on this event
+ *     should not block execution of other event handlers on this touch or other
+ *     simultaneous touches.
  * @return {!Array.<!Array>} Opaque data that can be passed to unbindEvent_.
  * @private
  */