It's not a dgVoodoo bug. dgVoodoo uses OutputDebugString to dump the debug messages. OutputDebugString relies on an exception-based implementation to transfer the string to the kernel.
If a debugger is present then the exception data is handed over to the debugger as a first-chance exception, and it is handled by the debugger and the game code continues running (that's why the _dbg version of dgVoodoo works with this game in a debugger).

However, when no debugger present (only DebugView), the exception intentionally generated by OutputDebugString causes Windows to walk the regular user mode SEH-chain on the game's stack.
Since that chain is already corrupted somewhere in the game, the walk triggers another exception (invalid SEH-chain) which ultimately crashes the game.