As I was getting in my S1 earlier, I caught the alarm button on the keyfob. However I didn’t think any more of it as it hadn’t armed since it didn’t go off when I got in.
I noticed a few people looking at the car as I was driving along but, again, thought nothing of it.
When I needed to indicate though, the green repeater on the dash only flashed once. The normal ‘clicking’ was evident however.
Putting it down to a possible electrical issue and priming myself for a weekend of fault tracing in the wiring, I was almost home when I pulled up behind another car at the traffic lights. I spotted my hazard lights flashing, but, checking the switch for those, it wasn’t the cause, so back to “bl**dy electrics” once more…
Yards from home I thought back about the alarm button… so pressed it and tried the indicators again. All restored to normal operation!
So let this be a lesson… check the obvious first and “DON’T TOUCH THAT BUTTON!!”
How odd, I wouldn’t have thought you could start/un-immobilise the car with the alarm active… but then nothing surprises me any more with Lotus electrics. 
Do you know if the alarm siren still works?