If compile-file returns a tertiary value of T, the file is not loaded.
This is not a huge issue per se, but lack of clear notification of the fact is IMO a problem: time can be wasted debugging, trying to figure out what went wrong, without ever realizing that the .fasl was never loaded.
A message is not visible enough: it's too easy to do something else and not notice it before it disappears -- I'd prefer something like:
Compilation of foo.lisp failed. Load the resulting fasl anyways? (y or n)
Cheers,
-- Nikodemus