Can vouch on his lecture skills as well, he was a visiting professor at UIC and taught my intro to combinatorics class. He was also very funny, his frequent stories would always make the class laugh.
The most amusing part about him was that he wore those tight biking shorts and shoes while he taught.
Here's an audio clip of Shai introducing Richard Stallman at a talk where Stallman gets pretty annoyed[0]
[0]: http://audio-video.gnu.org/audio/rms-speech-arsdigita2001.og...
He's a superb lecturer, and I owe him a debt of gratitude for his recorded classes.
[0]: http://www.aduni.org/
[1]: https://adunivids.neocities.org/
[2]: https://www.youtube.com/watch?v=Pt6GBVIifZA