On first sight (and not just after), pedantic is first word like.

According to Oxford Dictionary, Pedantic is someone who is:

Excessively concerned with minor details or rules; overscrupulous.

Some synonyms beginning with P : perfectionist, punctilious, precisionist.

Where do I find a saint?

Are synonymous words?

In your examples, the first sentence expresses planning while the second one shows a general expectation/promise.

One example:

1. Mary thought John was going to invite her to the party -> -> She thought he planned to invite her; she was on his guest list.

2. Why didn’t my mother want me to go to -> parties with John? Why was he a good friend and then a good friend and the second

example was

1. he told me the movie was going to start at 8:30. We think that was the result. -> The movie had started early, even though they thought it would. – plan
2. They thought the movie would start at 8:00. -> -> They were told from the start that that was the time it started. – expectation/promise

Check some more examples and explanations of future in the past in this page if you like. What more does this is and isn’t grand authority, but there is

good information.