Aww that's sad..but maybe it will still pull through.
I have done same booboo in watering with my lithops and split rock..forgot they were down the rack..oops..I almost drowned out the split rock
I am ever so careful with my plumie..still hoping to get one properly going. It looks like 4th attempt is showing better possibilities..keeping fingers crossed.
Hope you can shelter the plumie if it continues to rain.