I've never heard of this happening before, and I can't even think of a way in which uploading uLisp could break an Arduino, but contact me directly (my email address is on the uLisp site) and I'll try and help you sort it out.

I can't see how that would break it either, hence the low confidence percentage!

You could try to use another Arduino as an ISP and reflash the bootloader:

https://www.arduino.cc/en/Tutorial/ArduinoISP

connect reset to ground and try like that

I've tried that. Lights simply stay lit as if nothing's happened.

Sounds like you may have to reset the bootloader.