'Dryad Bronze Medal', perhaps?
I think all snowdrops will do this occasionally, a few do it quite frequently and I imagine that there are some that we don't cultivate that do it pretty much all the time. I'm sure if this snowdrop were prone to this aberrance then Anne would have not allowed it to get to market. 'James Backhouse' tends to throw extra petals, including from behind the receptacle, amongst other oddities. I tend to use that indicator to recognise it.