I would share their side as well, but I never heard it. This is a violation of their own code of conduct, which requires them to notify the affected person, explain why, and offer the opportunity to mediate the situation. This is not the first time I was banned from the Go community without notice or explanation, and the first time turned out to be frivolous -- the ban was overturned months later with an admission that it was never justified in the first place. Community management in Go strikes me as very insular and unprofessional.
Regardless, I don't really want to re-litigate it here. The main issue is that Google has been DoS'ing SourceHut's servers for two years, and I think we can all agree that there is no conduct violation for which DoS'ing your servers is a valid recourse.