When Google Calendar Didn't React to My Cancelled Flight

Stage 1 - Exposition
As an individual who plans everything on Google Calendar, I have been its most needy fan. At the moment, I am about to check in for my flight to my dear friend Olina's for Thanksgiving. 

Stage 2 - Rising Action
The self-check-in machine says that my confirmation code does not exist. I check my email again — yes, there is a confirmation email, with a confirmation code. I am not happy. I have a confirmation code. My flight is marked on my Google Calendar, showing instant updates about its delay too. 

Stage 3 - Climax
After an agent from the airline company approaches me and takes some time looking my information up, he decides to call their company backend to check my situation for me. It turns out that I changed my flight unintentionally to another date. I don't have a flight to my friend's anymore, one day before the Thanksgiving day. I tell the agent that I can pay the difference, as long as there is still a seat. 

Stage 4 - Falling Action
Yes, they do have a seat. I paid. But all I can think about is to get on that plane and call the airline company later to argue my money back. It's not the agent's fault, he is just being helpful and wants me to get to my friend's for Thanksgiving. There must be some bug in the backend. 

Stage 5 - Resolution
I pass the security check, flip on my Mac, get connected to the Pittsburgh Airport free wifi (sponsored by Duolingo), and log onto my Chrome (Google Calendar being my homepage). Google Calendar has invited me to see its update, a major interface update -- flat designed, colorful, app-assimilated. Nicely done

google calendar screenshot

I decide to check my email threads again before I call the airline company as an innocent customer to argue for her money. And then...I find out that there is a second confirmation email, which indicates my flight to be on another day. But I have missed this second email all this time. And plus, since Google Calendar still shows the original flight on my calendar, based on the first confirmation email I received, and I thought I was still bound to leave. 

It is my mistake then, not the airline company's.

Or is it Google Calendar's?