My gut feel has always been that Thomas as a Quaker did not actively participate in the Revolution as did his sons William, John and James Lindley.
The only fact I have ever seen to indicate that he supported the Regulators is an item from the "History of Hillsboro, Orange County, North Carolina," the Regulators took 39 barrels of flour from the Lindley Mill on September 14, 1781. At this time Thomas Lindley had a store and post office in his home, known as the Lindley Store. Thomas died on the 13th or 14th of September so this transaction probably took place after his death.
Had Thomas been an active participant I don't beleive that the Quakers would have allowed burial and ultimately allowed the stone monument for Thomas and Ruth to be placed at the Spring Burial Ground. He, like many others would have been disowned for participation in the war.
If you are descended from John and Sarah Pyle Lindley I believe that the DAR has recently accepted John's lineage for membership.