Comment # 32 on bug 1158817 from Martin Wilck

(In reply to Giacomo Comes from comment #26)
> > Yes. But without any firewall rules, disabling br_netfilter wouldn't have
> > any effect, either. The only purpose of br_netfilter is to call netfilter
> > rules for bridged packets, and that would have no effect if there were no
> > rules.
> 
> Apparently that's not the case. Without any firewall rules it makes a
> difference if br_netfilter is enabled or not. At least for this bug.

Jiri, does this make any sense to you? How could it come to pass?