WelcomeBot sometimes welcomes twice

[simonv3]

Two instances:

http://irclogs.jackgrigg.com/irc.freenode.net/openhatch/2015-04-11#i_3612706
http://irclogs.jackgrigg.com/irc.freenode.net/openhatch/2015-04-13#i_3613671

Does the database reset sometimes? I've accessed the openhatch IRC in the meantime and didn't get welcomed then.