Summer tires can indeed be tricky during wet/cold conditions. I just replaced the winter tires on the M5 with summer hi-perf tires .. perhaps a little early for SW Germany, however with warm weather already here, others made the switch weeks ago. Plus, tommorow I'm making the one hour trek to Nürburgring.

Looking at your picture, the damage doesn't appear to be as bad as it could've been. More importantly I'm glad you're able to type about your experience. Thank you for sharing it with us.
Best wishes.