Yep. Nuke it. Seriously, if you have the time, and you have even the slightest bit of doubt, why trust something that has been compromised in potentially unknown ways?
I like to think of it this way. You had a rootkit. It's gone, sure, but it could have been:
1. A symptom of another, larger, problem that wasn't actually fixed.
2. An as-yet undiscovered variant of this rootkit that had secondary effects.
3. Used to Do Something to your system before you removed it, and that Something wasn't removed (because it isn't detected as part of the rootkit payload).
You never know. I'd play it safe.
I like to think of it this way. You had a rootkit. It's gone, sure, but it could have been:
1. A symptom of another, larger, problem that wasn't actually fixed.
2. An as-yet undiscovered variant of this rootkit that had secondary effects.
3. Used to Do Something to your system before you removed it, and that Something wasn't removed (because it isn't detected as part of the rootkit payload).
You never know. I'd play it safe.