I live in the heard of Vienna and near the international most recognized restaurant serving Wiener Schnitzel. Figlmüller serves at the same location for over 100 years the original only 100 Meter from my office.
I have frequent lunch there - and also visited their kitchen.
The true secret is, that the crumbs must rise and separate themselves like clouds from the meat.
- thats achieved by:
- cutting from a special part of the veal
- flatten it with a special tool until very thin
- coat the Schnitzel with a layer of flour, egg wash and crumps
- using special Kaisersemmel breadcrumbs to cover
- fry the Schnitzel no longer the 30 seconds in total in three different pans with the same exactly 170º Celsius. Thats to keep the oil/butter temperature for the Schnitzel perfect stable (reason: the oil temperature goes down when a Schnitzel is placed in the oil - so another pan with 170º is ready to go)
The Schnitzel spends 10 seconds in each pan.
...and only then you will have a original Wiener Schnitzel - with a breading flying over the meat like a cumulus.

But there is more:
The true Wiener Schnitzel may be the original but a Schnitzel cut from pork instead of veal is (not only imho) far more succulent und tastier, comparable to its dry veal cousin. The drawback is that the breading doesn’t puff as nice. The upside besides is also the better price.
Thats the reason why even the first class restaurant Figlmüller serves „Figlmüller Schnitzel“ from pork - as the expression „Wiener Schnitzel“ is legally bound to veal only and may also only be advertised or sold as pork.
Originally Wiener Schnitzel is never served with french fries but with parsley potato or potato salad.
Sadly many restaurants give in and offer French fries with Wiener Schnitzel as (especially German) tourists demand so.
If they serve it with French fries, you can be sure the restaurant is not one of the best.