Hi Angela,
I thoughtfully read through the entirety of the other post and I'll offer my opinion:
If this was my ancestor, I wouldn't hesitate for a moment to list them as a Revolutionary War participant. Qualification for DAR/SAR doesn't require military service; service can be based on taking an oath or affirmation (entire counties were given oaths), paying a tax to support the cause, offering supplies to the cause or sheltering soldiers, etc.
I remember an episode of "Who do you think you are," the episode with Rob Lowe. They found out his ancestor was a soldier in the war and he was excited to learn he could join SAR. Then, they told him that his ancestor was a Hessian, a British mercenary. He was captured, if I remember correctly, in the George Washington Christmas Eve raid. Some of the Patriots wanted to treat the POWs badly but Washington was wise and he offered them clemency and even offered their freedom if they wished to stay in the states. Rob Lowe's ancestor stayed and later, he paid a tax to the cause and they presented Rob with a certificate that he was now a SAR member.
This letter, says he served as a soldier in the war - an irregular soldier, but certainly more than paying a tax or taking an oath.