I think he means the colloquial or informal use of 'get' to replace the auxilliary very 'be', which is common in BE:
His car got stolen.
The man got hurt in the accident.
The work got done in the end.
Basically, we replace 'be' with 'get' in informal English, especially spoken English. The rest of the sentence stays the same.
'Got' can, just about, be used in the passive, but usually as a phrasal verb:
They got at (teased, treated badly) him.
He was got at.
However, this is about the only example I can think of off the top of my head. ;-)