I have some more period mistakes for you. These have proven popular, so why not? The two for tonight are ones I have used in lectures many times, and they were in an article I did for American Furniture in 2002. (but that’s now 10 years ago – I guess I better stop thinking of that article as recent.)
First up, a nice chair/table from Plymouth Colony; probably late 17th century. Maple & oak. Looks good from here, right?

When I saw this years ago, I scootched down underneath it, and found this mortise chopped in the turned section.

It took me a while to understand it, but my guess is that the joiner did his mortising in the squared stock, then did his turned decoration.
In this case, the mortise was chopped in the wrong place, he went ahead & re-cut the proper mortise, then turned the stile as if nothing had happened. Didn’t plug it, patch it – nothing. Just left a gaping hole in the stile. I like it.
I got very excited when I deduced this order of work; mortising, then turning. So much so that I have done it that way in my shop ever since. Then, after about 6 years of doing it that way, I finally thought, “Great – now I’m taking lessons from some guy who couldn’t even get it right!” (and he was using maple…)
At least this next one is oak…

side view cabinet; w crack at upper hinge
This side view of a small cabinet shows a nice crack where the upper hinge is nailed onto the case. Being a semi-coherent joiner, the guy skipped the nail that lined right up with the crack; leaving that hinge with just 3 nails to hold it in place. I couldn’t decide whether the crack stemmed from boring & nailing the hinge in place, or nailing the top board down onto the ends of the sides. Either could have split the 3/8” -1/2” thick stock.
But, open the door to the cabinet & you see that the joiner, just to be safe, took the extra nail & drove it through the edge of the cabinet side, effectively closing the crack. It’s held since 1679. not bad.

nail driven into edge of cabinet side
Here’s a detail:

So these are some of the reasons why I don’t get too worried about woodworking. It’s easy once you relax…and then, whoops.