Thx guys.

Just patched the flat, it was a slightly curved tear about an inch long. It was covered nicely by one of the larger, rectantular patches, and the vulcanization seems to be holding.

I thought the tire pressure was fine before at 30psi front, 35 back (in terms of eyeballing something like 15% tire drop on the asphalt, the famous chart doesn't go to 50mm), but I guess it wasn't enough for this case. I jacked it up to 35/40. I expect it to still be a cadillac-smooth ride on the asphalt.