The incident happened just after 2pm on December 27, 2012.
Fortunately a nurse was passing by and was able to help the man before emergency services arrived.
The man who did it escaped through the bus window.
The man he kicked was left with severe spinal injuries and is currently paralysed.
The show catalogues just a few of the tens of thousands of crimes committed on London's buses every year.
You can watch it here.