[rbehrends]

First, how do you know that no data was lost? There is no way to even verify that all data was recovered. They are pretty confident, but there's really no guarantee, is there?

More generally, yes, the case you are worried about is typically not when there are lots of repository clones in circulation (though the KDE case [1] shows that data loss is quite possible even then and that replication is no real alternative for proper backups [2]).

And, of course, the reflog will keep commits alive for a while and garbage collection will not occur while the grace period is over.

The situation where this doesn't work so well is personal/small group repositories or branches that only experience intermittent commits and that aren't being mirrored by a large number of users. In that case, user errors can easily translate into data loss when garbage collection finally catches up with you.

[1] http://jefferai.org/2013/03/29/distillation/

[2] A practical example would be where a repository is so large that many contributors prefer to use shallow clones.