Am a bit late to this party but is looks like you've done the right thing.
It seems the Zeds throw engine management lights at the drop of a hat, frequently for spurious and transient reasons.
Its clear that some sensor errors put the car into limp-home mode and it won't come back without clearing the codes - just what you've done.
I had mine come on towards the end of last year - I just happened to have my GoPro in the car and that captured it coming on - it reported a camshaft sensor code (if I remember correctly) which was coincident with going over a huge bump in the road. It was off one frame and on the next just as the outside view went wildly blurred. Cleared it and it stayed off. Just like your experience, but, looks like you had a sensor report that the ECU thinks is more serious if it faults so it acts to protect the engine.
Last week mine came on again, more or less at the same bit of road. Same again me thinks. However, there were no codes reported (at least on the reader I have). Carried on driving it and it went out all on its own while I was out on Sunday going up to see
@t-tony - I had filled the car up previously with Tesco 99. On Sunday it was back to a tankful of 95RON fuel (not paying the £1.35 or more per l at the local garage). 55 miles into the trip, the light just goes out!
Both times the the light came on the car ran fine. Looks like this time the fuel caused something to get bitter and twisted - but no codes?
A code reader of some kind (that can also be used to reset codes) it seems is an essential bit of kit. Highly strung cars need a little more "listening to" and reassuring noises that you are listening!