Blackened Tomato leaves, looks like blight

The picture below shows some of the damage on just one of my plants. I've been nipping off bits of leaves and trusses as they have been turning black.
This morning it was looking to be spreading so pulled up the plant. It looks like blight but it seems to be systemic in just the 1 plant with bits of damage in several places.
One good thing about it is that it is a roma vf and the root system is really good even when planted where all other varieties I've grown there die off early from wilt. Another roma is next to it that is looking very healthy.

No blight at all on any outdoor potatoes which is where I would have thought it to strike if anywhere.

   

Is that in a greenhouse? Are you sure it wasn't botrytis? Lack of ventilation?

Could be botrytis, but only one plant and it seems to be quite aggressive and the plant was next but one to the double doors of the greenhouse which are open most of the time now. Botrytis and blight, I would have expected to move to other plants but not so far.