Black spots and speckles on Cattleya leaf

[practicaldreamer]

I'm not sure how I missed this until today, but one of my Cattleyas (Lc Green Veil "Dressy") has a bunch of blackish dots and speckles on the underside of one leaf. This particular bulb previously had two leaves but I removed the other when I bought it a month or so ago because it was wobbly and didn't seem extremely healthy. The other leaves seem unaffected, at least for now.

Needless to say, I'm concerned...I sprayed it with fungicide, but should I cut this leaf off all together? Does this look like it might be a fungal or bacterial infection? Any insight is greatly appreciated!