You just figured out what the problem is with "overcooking" something in the pressure cooker - basically, all of the liquid from the meat went into the cooking liquid and made a pretty delicious stock. No amount of additional pressure cooking is going to put the liquid back in the meat leaving just a hunk of tough, dry fibers.
There are a couple issues that gave you tough dry meat from the pressure cooker.
The first problem is the cooking time - the 25 minutes recommended on the site you linked to excessive. You didn't specify what cut of meat you used but you gave the cooking time they recommended for a beef steak - I recommend pressure cooking this cut of meat for just 10-15 minutes.
Another important part of figuring out how long to pressure cook something is to understand what pressure your pressure cooker can reach, and for what pressure the time chart you are using is written for. There are no indications on the chart you linked to for what pressure that cooking time is recommended. That's not helpful.
Usually the best source for the right cooking time is your pressure cooker's booklet- most include common cooking times. Next time, I would look there first.
The second problem is using too much cooking liquid. It sounds like you wanted to make a "braising" type recipe and ended up with boiled meat. The way to braise meat in the pressure cooker is to use the minimum amount of liquid your pressure cooker needs to reach and maintain pressure (also called minimum liquid requirement). You'll find what that quantity is in your manual, too. But generally it's 1 cup for stovetop and 1 1/2 cups for electric pressure cookers.