If the event is live, there is no undo that I have found.
Not like I've never done that. :)
In situations where I need to correct a mistake I have added a custom contact field. Name it whatever you want.
Export the invitees, first name, last name and source id (or email). Enter whatever makes sense in the custom contact field.
The last time I needed to do this I entered KEEP and DELETE in the column.
Import back into the address book updating records.
Then you may be able to filter out those unwanted invitees based on the custom contact field.
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Steven Schlossman
Jack of all trades. Master of none.
BMW Car Club of America
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