load-system permanently alters sb-c:compile-file behavior on SBCL 2.0.9
Calling asdf:load-system alters the behavior of SBCL's sb-c:compile-file. After load-system is called, compile-file no longer detects compilation errors while compiling. I've no idea why this should be the case, nor if it is expected behavior (does ASDF change compilation/optimization settings?)
I've created a minimal test case demonstrating the problem here. I've tested it on SBCL 2.0.9 using the version of ASDF bundled with that release.