Andrew Tridgell maintains that he didn't violate the terms of BK license. The story of his 'reverse engineering' of BK is necessary to understand the context: https://lwn.net/Articles/132938/
It also seems unlikely that that was where it stopped, as that likely wouldn't have gotten any attention. The whole claim just seems disingenuous.
One can be fulfilling one's curiosity in simple and obvious ways and still be breaking license terms or the law. That something is trivial doesn't mean that it is moral, legal or licensed.
In good news, the supreme court clarified/limited the CFAA in June 2021 [1], so it's now seemingly legal to access a server however you like as long as you're not accessing information you wouldn't otherwise have access to.
[1] https://www.theverge.com/2021/6/5/22491859/supreme-court-van...
That would be surprising to me. Being a DCVS, lots of folks in the community would be running their own servers and sharing the URLs to them; that is were Andrew would have noticed URLs like bk://thunk.org:5000. For instance, here's one such URL being shared on the LKML where Andrew hung out: https://www.cs.helsinki.fi/linux/linux-kernel/2003-12/1108.h... It is my assumption that bk.arm.linux.org.ku was not owned BitMover.
Perhaps that means that whoever was running the server than Andrew connected to was in violation of their license by "authorizing" Andrew's access.
Note that the CFAA is a criminal law, so it was possible for Andrew to be prosecuted for breaking it, given a report to the police, if he hadn't been given direct permission to access that server in that way, whether or not the server owner minded.
"It was not, he says, an act of wizardly reverse engineering."
The word "wizardly" is important here. He's denying reverse engineering, only that the reverse engineering wasn't "wizardly," or basically anything magical or special. Just plain old curiosity.
Basically, the browser version of view source.