This is NOT a bug. While I agree that the behavior is a tad annoying at times, it is clear that the system is working exactly as intended - a bug would be behavior contrary to design. I will try to explain why:
I have two calendars added that are not iCloud calendars. One is an iCal file that I added manually, the other is a subscribed calendar. The manually added calendar (the 2014/15 NHL Schedule) was published in EST and the phone correctly imported the calendar and displays the events according to my local time zone. The subscribed calendar was published in GMT as are many of this type, yet again the events display correctly in my local time zone.
If I create an event in my local time zone then either travel to another time zone, or manually set my phone to another time zone, lo and behold the phone exhibits the same behavior - times are listed in my original time zone and editable in my original time zone (this is very handy if you are away on business but need to update an event for when you return to the office).
Google calendars store all events (evidently) in GMT and display them to the users according to their timezone setting on the website or in the appropriate app. Since iOS has no way of knowing to which time zone your Google account is set, it displays the events in local time but they are editable in GMT.
So, if this isn't a bug, what is it? Well, the community clearly desires a different behavior from the product and therefore this is a feature request or requirement. Unfortunately, bugs will take precedence over new features in future software releases so if Apple is aware that users are unhappy with this NORMAL behavior it may take a while before it is changed.