Here all three are equally responsible.
1. Tanker was moving to left lane,
Bus driver forced to reconsider. Tanker driver didn’t check the right mirror.
2. Bus driver show car is overtaking from right still forced Tanker driver to right.
1/2
Both are equally at fault. That’s why I always say use both side mirrors while changing lanes and always honk before overtaking.
In India, honking isn’t noise, it’s survival.
The truck driver moved right after spotting the bus but didn’t check his mirror, while the Innova driver tried to overtake without honking! ☺️