"Or was it?"
This is a question to add doubt to a sentence, or to add another posibility.
The question can be put into a sentence to make the user seem unsure about a statement. This is rarerly used in writing, but is often used in speach.
An example of its use would be:
"I was walking home on Tuesday, or was it Thursday?"
In this sentence, the person is unsure when they were walking home. They say that it was a Tuesday, but then afterwards, they think that it may have been a Thursday.
More often in writing you would find it at the begining of a question, adding another possibility.
"Why did Mrs. Jones travel on the bus? Was it because she liked talking to the other people? Or was it because she thought it was cheaper?"
In this example. The first question asks a simple question. The second question suggests an answer. The third suggests an alternative answer by using "Or was it..".