This is an unfortunate workaround which is necessary because an instance of dcrwallet will only recognise a ticket as revoked if it has done the revoke itself. If another wallet broadcasts the revoke then the ticket will forever be reported as missed/expired. This causes problems for vspd when a wallet outside of the vspd deployment revokes a ticket (eg. a users ticketbuyer wallet).
I'm happy to include this slightly dirty workaround because this should no longer be an issue when the auto-revoke work in DCP-0009 lands.