We have done the very same thing, and on the very same bike. The Gulfstream with its long wheelbase (106") is not fond of sharp low speed corrners. It's not just the gulfstream I've done the same thing on our screamer as well as our off road tandem and don't ask about the quad.... but never the trike...Hmmmm
If your tire was soft the tire could have rolled off the rim, that would have put you on the ground fast. Or maybe you hit a manhole cover? I did that on the Slipstream, did not crash but it was close!
We run a very large tire on our gulfstream 2" or better. The bike handles much better and is more stable. Infact we just finished the Great Allegheny Passage on the gulfstream towing a BOB and bike did fine on the crushed limestone.
At the time did you have a stoker on the bike with you?
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Bentbaggerlen
"When the spirits are low, when the day appears dark, when work becomes monotonous, when hope hardly seems worth having, just mount a bicycle and go out for a spin down the road, without thought on anything but the ride you are taking." - Arthur Conan Doyle