Assume this template

<ul>
  <li !if="exp" (tap)="doSomething()"></li>
<ul>

Here the li will get turned into:

<template>
  <li !if="exp" (tap)="doSomething()"></li>
</template>

Once the View of the if gets instantiated it will attempt to register a tap event on Hammer. The issue is that the element is a clone of the <template> and is not yet inserted into the main document for rendering. Hammer will than try to register a listener on the wrong document, which is null.

(See hammer.js)

function getWindowForElement(element) {
    var doc = element.ownerDocument;
    return (doc.defaultView || doc.parentWindow);
}

The issue is that the doc.defaultView is null since the ownerDocument is that of the template and not of the main document.

Proposed Fix

Use document.importNode(element, true) instead of element.cloneNode(true)