White Strawberry Cheesecake Auto

How many leaves effected was it just this one ? it doesn't look like a defenancy of any kind to me it looks more on the lines of a nasty pathogen or fungus spores I know that sounds very drastic but I'm just being honest if this is the only leaf effected and you have removed it and binned it then you have already done the correct course of action and you should have nothing to worry about going forward I would advise just to clean everything down as best you can and you should not run into any more of this. If its showing all over the plant then ph fluctuations can cause similar symptoms to this.