Symbian panic does not cause the debugger to be invoked when debugging from Codewarrior. Instead the emulator shows the normal Panic dialog. Ideally one would want to see the callstack at this point in time, so one can see which line caused the panic.
It seems that this problem occurs when the panic happens in another thread (a server) than the main application thread. When a panic occurs in the app, the debugger traps the event!
It's probably the way the emulator was built. Normally when the emulator wants a thread to be halted in the debugger it hard-codes a breakpoint instruction.