While 90% of the time you may not have to worry about special cases, if you find the need to , you'll have to do a lot of code modification in order to get the special case to work.
Most of the items that Fatal is advertised for only return a "success/fail" value so it is completely trivial to handle the 10% cases. If you look at the return value, then the call isn't fatal. If you don't look at the return value, then the call is fatal.
Calls that return vital information that can also be an error indication aren't as well suited for the type of error handling change that Fatal imposes and so I don't include those in my proposal above. Note that some of the calls do return information, but that information is not vital.
For example, I don't include fork because there usually isn't much point in calling fork in a void context. Since you pretty much have to check the return value from fork (to decide if you are now the parent or the child), you usually also manage to check for the error case. The value returned by fork is "vital".
Now, some invocations of open can return interesting information, such as a process ID. But that information isn't vital. It is very common to check the return value of open only for whether it failed or not. And people (unfortunately) often use open in a void context. So making open (in a void context) "fatal" can be a great way to find hidden errors.
(but my friends call me "Tye")