Cause traceable, a criminal complaint and compensation are possible.
If the cause is known, two strands are available. Under criminal law, riding off without helping can amount to leaving an injured person behind under section 95 StGB or failure to render assistance under section 94 StGB. Under civil law, a culpable breach of the FIS rules gives rise to a compensation claim under sections 1293 et seq ABGB.
Next steps: secure the identity and witnesses, file a complaint with the police and collect the treatment and damage records.