Shutdown Panic in ban causing fellow to become corrupted

I have witnessed this a few times in our lab over the last few months, but this is the first time I was able to get any actionable information regarding what was going on.

The steps here have been to shutdown varnish, during shutdown it panics. When attempting to restart Varnish, it fails to start up and enters a panic cycle.

I'm unsure what the cause of this would be other than comments regarding small memory regions made in #102 (closed) but this feels very different.

I will attach what debugging information I have.