Resetting the server doesn't solve the problem, lag is there immediately after restarts including raids. It's less noticeable than at night with more activity but I feel it whether or not a server has restarted.
What I will agree on being a development of program myself, is that memory usage is high. Usually means spaghetti of code that isn't efficient. With an old game like this, there's a good chunk of spaghetti code that's inefficient that causes high memory usage or spikes in memory usage.
Memory leaks are what occurs when swapping between loading screens. Completely different.
Memory leak is a bug where allocated memory is not released, and it's not limited to just loading screens.
Furthermore, it's not only a DDO bug.
Furthermore, the issues caused by memory leaks aren't limited to just memory constraints.
Neglecting to release memory that should be freed can lead to additional tasks being generated and ultimately result in processing delays.
So, don't think of memory leaks solely as memory constraints.
Ultimately, whatever outsiders say is just speculation, you know.