maybe I can suggest to you a way to circumvent the problem.
Why are you keeping a local Calendar copy under "my Mac"?
I do have my calendar shared through iCloud between my Mac Mountain Lion, the iPhone and the iPad (both alread IOS7) but don't need to keep any local copy of it in neither device. Anyway I'm able to see the calendar on each device even if I'm offline.
That's way I never had the problem you mentioned.
Not sure if this would work for you as well.
Sorry if I was not clear but the calendar is already on an iCloud account. I assume that internally there is a local cached calendar that syncs with iCal on iCloud otherwise you would not be able to perform any changes whilst off-line.
Hence I think that there is a problem when the local cache refreshes the iCloud data.
I am having the exact same issue. It's causing major issues and am thinking of switching to another calendar tool. I worked with Apple on this a few months ago and they suggested I only accept updated via my iPhone vs. my macbook pro. I am not always able to do this and so the problems persist. This bug is on Apple's radar; they claimed incompatibility to be the cause.