I think perhaps you're being overly pedantic, missing a free, or leaving a reference to no longer used memory has the same result for the application, the heap grows and eventually causes problems.

I run a distributed embedded Linux systems, and we use both C and Lua which is GCed. We track heap use from both Lua and C daemons for pretty much exactly the same reason. Both C and Lua apps can leak and I need to know if we've got a problem in field.

Our biggest problem in C is Jansson and keeping track of all the borrows vs steals of references. Lua is so dynamic it's sometimes easy to lose track of someone holding a reference for too long or forever. When you mix in closures, sometimes it's not always clear what the lifetime will be, especially if the result or error never happens.