Meg is turning 17 but it's been established earlier on in the series that she was already 17.
Stewie knocks over a glass of juice but the glass does not shatter, even though the sound of glass smashing is heard.
When Peter's taxi arrives outside the pub, it's in the righthand lane. As in the UK, Irish cars drive on the left.
Mickey McFinnigan is his real father not Francis Griffin. This means that Peter is can't be related to any ancestor he tells but he could have been making it up but that also doesn't explain why he look like a white version of Nate griffin.