I've seen a Bittern by the parking lot, but not a Rail.
However, I think that there are many Rails scuttling about around the ponds. They are easily spooked. If they become accustomed to your presence, they will walk out in the open, occasionally eyeing the viewer.
Last year I heard one out where a net is and walked over to the water's edge. Then stood very still. Within a few seconds, the Rail started a low volume series of sounds and began walking around. It came to within 3 meters of me several times. I'm certain that if I moved it would have disappeared in a flash. I suspect too many Birders become excited and make a fast movement which promptly ends the experience.
I watched a pair at Colony Farm busy making a nest recently. Every time they had to leave cover, they picked up speed and darted across the open area too fast to aim a camera at them. They never used the same route twice, making a prediction difficult. On this occasion there were 3 or 4 people watching them and I suspect this made them more uneasy than usual.
I discovered a couple of tricks to get them to reveal their approximate location. On Sunday at Iona at the back of the pond referenced above, I heard one doing its Three Stooges imitation. I looked at the area where it likely was and noticed a small clear patch. I watched this area for a few seconds and sure enough, a Rail moved across, in the open for a few seconds. I then moved slightly to get a better view of this clear area and simply waited, NOT MOVING. In a minute or so, out it came again, this time cautiously viewing me as I was closer (5 meters perhaps). It moved slowly enough for me to take some partially obscured photos before disappearing into the thick ground foliage. (I've heard them in both ponds at various points.) Photo of this one below.