on-click/tap still works if disabled is true.

[matthiasgoossens]

The on-tap event still works if you have disabled attribute set to true. Don't know if this is expected behavior?

[fxedel]

Correct. For example, the paper-icon-button component sets pointer-events: none when disabled to avoid the click event being fired. I'll add this after migrating to Polymer 3.0 (#20) – shouldn't be that complicated.