When I was at T-Bar and spoke at length with the Fazio brothers, Al and Richard, they never mentioned a second entrance to the beach area - only the gated one that Al escorted me to. He said that they used to have a jar at the gate for people to make a contribution - 25 cents in 1971. Al said they stopped the practice shortly after the money find due to the increasing number of people misusing the beach, littering, drugs, etc. Too much hassle and liability. But before hand, the beach had unlimited access, and was well-known to locals as a place to go for free, or cheap at two-bits.
As a result, T-Bar was used frequently, mostly by fishermen.
Apparently there are multiple access points to the strand. I met a fisherman on the beach north of the Fazios and I understood him to say that he was on his land. So presumably he had his own access, parking, etc.
As far as I know, I am the only Coop guy to go swimming at T-Bar, as it was 105 degrees when I was there. Water was delightful, but the current was amazingly strong. Scary, even. Very bizarre to be swimming and see a freighter go by. At the Frenchman's Bar County Park, thousands of folks go swimming in the Columbia, and the lifeguards patrol the swimming area on jet skis. Interesting.
Lastly, I have no idea where Paul was walking and filming. But it was Columbia-ish.