Looks like a datafeed error. Euro, kiwi and AUD/NZD cross all had massive spikes at about the same time, 1:45 pm EST. None of the EUR crosses I checked are affected.
Anyone whose stop loss was triggered should call Oanda to have it undone. (An additional argument for not entering stop losses in any forex platform unless you are going to be away from your screens for hours.) If your target profit was filled, just keep quiet , although it may not stand anyway.
Just spoke to Oanda. Yep, these were errors, which I'm told they are in the process of undoing. For anyone affected, no need to contact them, unless your particular stop loss is not undone as expected.