expansion panel disappears if you click quickly on something triggering a collapse

[sschick-prognos]

Noticed this in my own code where I'd done something a little goofy to make the panel collapse if it was clicked on when it was open. However, the plunkr that @iamempty put together in a different bug also replicates the problem. I've reduced it a little bit for clarity below. The bug only triggers when clicking quickly on an element that will trigger the panel collapsing with a touchpad (a mouse does not trigger the issue). It looks to me like it is triggered when there is a close and then open event in very quick succession.

http://plnkr.co/edit/lmzkgzQKVNfdGh6uswrx?p=preview

[sschick-prognos]

After a little fiddling with my own code, I found that running panel.collapse().then(panel.collapse) successfully masks the problem (with a little bit of an odd flash of the element). It would still be great if this could be addressed more elegantly.

[B-3PO]

I am not exactly clear on how to reproduce this error, can you give me some more info.

1. steps to reproduce
2. browsers you are seeing the issue in
3. os

[mrs-eload]

Happened to me too when toggle collapsing/expanding from the header.
Looks like css has difficulties to be updated when quickly expanding and collapsing. Animations are probably overlapping.

@B-3PO
ng-click="$panel.collapse()" on md-expansion-panel-header then massive clicks on panel header.
Sometimes panels disappear, sometimes one or more elements are staying.
@sschick-prognos code is exactly like mine but can't reproduce the bug on plunker though.
Oh and the workaround is working, thank you :)