Not sure what happened. Winds can be tricky down there though. Fortunately nobody got hurt.
For the longest time, I wasn't sure either, and just blamed myself as a new owner/low time tailwheel pilot, which was true, but not the whole story. So that others might learn from my experience:
After getting the plane back from an extensive first annual, I flew my son to 26N for breakfast.
Beautiful day, uneventful flight. We set up for 24, direct xwind from the right but not too bad. Unremarkable pattern and approach. Bounced my wheel landing, but not badly.
Got the tail down, got on the brakes, and the plane abruptly veered to the right. Isn't this how ground loops start? I applied left rudder, but it didn't straighten out. * Weird. I added throttle to get more air over the tail, still nothing. Uhoh!
When it became clear that we were going to leave the runway, I attempted to go around, but the plane did not achieve flying speed**. After offroading briefly, we came to rest in a stand of reeds and pivoted into a nose low attitude. Thank you, Hooker Harnesses!
I saw gas trickling out of the vent and down the windshield and decided it would be a good time to get out. I kicked the door open, hopped out, unbuckled my son, and got him out.
The paramedics were great. Free Gatorade!
My wife was great. I called her and explained that we were okay but we were unable to fly back home and that she should get in the car with our younger son and drive the three hours to pick us up. She loves terse, ambiguous messages like that.
Then, the walk of shame to the FBO. A helpful onlooker reminded me "it's called a crosswind!". The diner was great. Free lunch if you crash your plane and NOTAM the airport closed!
The Philly FSDO was great, insurance was great, as were the folks at 26N, as were the folks at Woodbine who had to fix the thing on the ramp. Engine teardown, new prop, and of course a couple of "while you're in there" things that I shouldn't have bothered with.
The complete answer would be revealed in 2020, when I had a brake drag on me while taxiing, to the point that it started smoking (which then reminded me of the dragging brake incidents that happened in 2018 when I first got the plane and was receiving transition training in it; I THOUGHT the issue had been fixed by servicing the calipers, but as a brand new owner, I didn't know what I didn't know). At that point, I'd had enough, so I went to a nearby shop and asked them to overhaul my master cylinders. One was not vented, the other had a broken spring. Replaced them both. I later had the flex hoses replaced, and the brake issues finally went away.
* mistake 1: I should have applied left brake to straighten it out. It wouldn't have fixed the brake issue, but we wouldn't have crashed, at least not at 26N.
** mistake 2: In the moment, I failed to push in the carb heat and pick up the flaps.
