[marlboro man]

I added a white flat purple tip anemone 3 weeks ago and it was doing fine.
Then 4 days ago I added a Red BTA, which was also doing well.

Then 2 days ago, my white flat anemone excreted some brown slime. I tried to scoop out most of these slime. But most of it dispersed throughout my tank. Then unexpectedly my white flat anemone shrank this morning and started closing up(rolled into a ball shape). By tonight, my BTA also deflated.

I just checked the water and everything seems fine. Even the polyps of my yellow finger gorgonian stayed open so water should be ok.

1)Is it possible that the two anmones are having chemical warfare with each other? (they never came in contact with another though)
2)Or could the brown poop from my white flat anemone be the cause for my BTA's sickness?
3)or could my white flat tip is dying and the toxin is killing my BTA? (but then everything in my tank seems fine and healthy)

Pls help me.
I am doing a water change now