Chuck I don't believe that for a moment. My family has been in the timber business for generations and during my career as an attorney I represented, growers, loggers and mill operators. When there is a market demand for a certain type of timber (red oak for cabinetry and floors for instance) there is no shortage of those willing to harvest and deliver logs to the mill. It is no more difficult to cut a white oak tree than a pine, dogwood or any other dry land timber. Cypress can be a bit tricky because it sorta grows in a swamp. The only difficulty in harvesting white oak is the trees sometimes grow on an incline but the technology to overcome that has been around since after WWII when all sorts of heavy duty surplus machinery became available.
Things slow down for everybody from the tree farmer to the mill owner when market demand goes soft such as when the housing market slows down. In times of high demand labor to harvest trees is the easiest obstacle to overcome.
I believe the barrel shortage is unique to that part of the industry that produces whisky barrels. I don't think they were prepared for the upswing in demand for their product and there is no reason they should have forseen it coming. As Mike corectly pointed out above the staves have to have a drying out period (they can be kilned of course but not everybody wants that sort of barrel) and heretofore the barrel makers didn't have the incentive to front the costs (insurance alone on a lot full of drying wood is tremendous) stockpiling stave wood when there wasn't an apparent market for the barrels.
Rainfall indeed, these guys work outdoors. The only thing that keeps loggers out of the woods during rain is lightning.