I think your payment hit a superblock (the blocks where a budget proposal was paid)  which, IMO should be repaired in the code.  I think it's so infrequent, that it wasn't a priority.  But I think these superblocks are coming more often, as we have many budgets being paid, and this will really start to impact everyone sooner or later (not to say your impact wasn't important) and will affect the masternode and mining income adversely.  I mean, does this only affect MNs?  Or also miners? 

It just needs to be fixed at the first opportunity imo