A Pecan tree in Owen Sound?

Preamble:  It was Ryan Patterson (the current OSCVI greenhouse guy) who first alerted me to two odd trees on the Billy Bishop Museum property.  He was first to tentatively identify one of them as being a Pecan tree (Carya illinoinensis).  Ryan has had some formal training in botany (I don't have his complete resume) and he has worked in Texas where apparently there are lots of Pecan trees.
My next step was to check the OSFN publication "Exploring an Urban Forest, Owen Sounds Heritage of Trees."  The Billy Bishop Museum entry (page 71) lists Norway Maple and Blue Spruce.  No help there.
My next step was to have a look myself.  There were two large trees, too tall to collect or examine the leaves.  However, from the ground, I was able to collect some half shells of nuts and what looked like whole mini-pecan nuts (that turned out later to be empty but still pecan-like on the inside).
I then phoned the Museum to ask them if they knew what kind of trees they were.  They did know that they had a pear tree out back.  I didn't bother asking them how they knew that.  (You would think that the "Museum Story" would be enhanced and that more interest in the Museum would be generated by having a description of the plants growing on the property - especially if they are unusual ones.)
My next step was to do research on the internet.  I came up with two tentative IDs, Heartnut (Juglans ailantifolia var. cordiformis) and Pecan (Carya illinoinensis).  Next, I went back to see if there was any reason to discard these choices.  I saw nothing.  I waited for the leaves to fall.  The Heartnut leaves have fallen and did look correct.  As of this date the leaves on the Pecan tree have not.  I intend to observe these two trees at least over the next year to test my conclusions.  This leads me to my

Main Thesis:  I believe it was Joe Johnson who first impressed on me that all IDs are tentative.  Taking samples of a plant and sending them to a herbarium for a comparative examination by an expert is the closest that you can come to the truth.  Something else I have read said that you should always try to put a name to a plant.  By doing that you are documenting its existence which is a good first step towards determining exactly what it is.
I like to think of my ID process as being an application of the Scientific Method.
Applying the Scientific method to my plant ID process:

1. I ask the question, "What is it?".
2. I assemble what evidence I can.
3. I make a tentative ID.
4. I assemble some information about the plant that I did not observe the first time.
5. I determine if this new information applies the plant in question (which might take a year or two - or more - of waiting time!).
6. I readjust my ID if necessary.  
7. I go to step 3 if I have changed my mind.
8. If I have got to this point I will now confidently state that (subject to being corrected) this plant is a "XXXXX".

If this process doesn't work, well then, obviously, I have found a new species.  However, rather than announcing that to the world, I ask for help. 

Confession:  I have not found any new species - although! - on lots of occasions I have asked for help.

Conclusion: I am wrong more than I would like but I have learned more from being wrong than I have from being right.  I think that's a pretty good trade-off.