Can hyaluronic acid fillers disfigure a face like the actress Jocelyn wildenstein if too much is used?

I can assure you her disfigured face was not done by Botox, but by botched treatments and silicone/cement of the like being injected. Highly skilled reputable offices would NEVER leave a patient disfigured as Joecyln Wildenstein preforming unscrupulous practices. Patients are our billboards, experience shows the natural results in patients allowing many friends and family of theirs not knowing any treatment was preformed. 

The person you mention had multiple surgeries , implants and filler treatments.  It would be possible to overfill areas of the face such as the cheeks or lips to the point of developing a cheek that obscures the eye and lips that look significantly larger than physiologically and anatomically normal. However most practical physicians will not overfill to that extent.
Cosmetic procedures when administered to rejuvenate and replace lost volume as a consequence of natural aging can give you a wonderful look. I recommend if you want to enter the pool find a local doctor with plenty of experience in the field who has a conservative philosophy and you should not worry about disfigurement