Tamil Nadu State Transport Corporation [TNSTC] — driver moved the vehicle while boarding..

Today (31-jan-19) my aunt was boarding stc bus route no.79 at varana vasi around 3.30 pm, the driver moved the vehicle before getting inside the bus 7 without conductor whistle indication. Due to this, she fell down from the steps & got injured. If anything went wrong way who is responsible??
This is a good way of public service???

Plz check with concern depot. Take necessary action against the driver. To avoid such kind of issues in future that happens to the public.

Plz do the needful..