You were booted for:

1. Turning yourself in to the Provost - that's just lame for imperial who see Tribs as their underdogs, and you're Elite, not Oath of Citizen level. Turning yourself in to the Provost was a sign of great weakness.

2. Being honest as Elite Shadow. That's just lame, read the sect rules, shadows are the slickiest of them all and by being naive and simple-hearted you've proven that you're no shadow.

3. Breaking Imperial Law by attacking in town (that is the least of the offenses you've commited).

4. Doing all that in Glik's watch who's the most hard-ass Emperor I've witnessed so far.

5. I bet you also let conjurer live, which is also lame. So you've just given your life away for nothing.