Package versions not respected?

[kenahoo]

The main point for me of using pak is that I can be sure that specified versions are respected: I manage production deployments where I need to strictly maintain dependency chains and ensure things are as they should be.

But I recently saw this part of the pak docs:

which seems to negate the whole point of having the version specifier.

I've seen this in practice, where I request a specific version of a package and a different version gets installed (here myPkg is a stand-in name for a local package from our local repository, but all the rest of the text is unmodified):

> pak::pkg_install("myPkg@2.104.3022540")        <------- 2.104.3022540 requested
✔ Loading metadata database ... done                                      
                                                                          
→ Will install 1 package.
→ The package (0 B) is cached.
+ myPkg   2.114-5739970 👷🏻‍♂️
ℹ No downloads are needed, 1 pkg is cached
✔ Installed myPkg 2.114-5739970  (21ms)             <------- 2.114-5739970 installed
✔ 1 pkg + 106 deps: kept 103, added 1 [6.2s]                               

Is there a summary of what situations will respect a version constraint, and what situations won't? I'd like to understand this better.