Hold on there mister, the Laschamp event only lasted less than 500 years, and occurred in the middle of an ice age, over 41,000 years ago. I don't know about you, but I see a whole lot of unknowns that make it very difficult to conclude that "the climate didn't change".
How much of the surface of the earth was already covered with ice/snow -unknown
How much of an increase in annual cloud cover over non-ice/snow regions did the planet experience during this event -unknown
How accurate are the ice cores in capturing relatively short events measuring hundreds, not thousands of years -unknown
How much variation was there during this event in terms of the strength of the field -unknown
I would prefer to not draw any conclusions from what little data we have of this event. We have the technology to measure GCR's, and we have the technology to measure cloud cover. Let's verify the theory of GCR's and cloud formation, let's quantify it, and then let's see if we can accurately predict cloud cover and irradiance fluctuations based on this data.