Well I some what agree that everything will be OK. But I don't know the conditions of the rubber hosing that is still under pressure from the tank. So I say it is better to be safe than sorry and do the "belt and suspenders routine". LP leaks fall to the floor and move to the lowest part of flooring usually in a corner. Find a way to get it shut or hope and pray every thing will be OK tomorrow
A personal experience last year on my John Deere lawn tractor I was working on getting ready for the start of spring time work outs. Noticed my fuel line needed replacing. Went to the parts store to buy fuel line. Came hone and found a gallon+ of fuel was all over the garage floor and fumes in the air. Said WTF to me and discovered D.A. me forgot to turn off the shutoff valve. This unit has a gravity feed fuel line with only the filter and shut off valve from the tank to carburetor. So this '44 model is now a "gun shy dog" when it comes to open fuel lines and once again adopted the belt & suspense approach of safety.

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nothing will happen unless you have a leak in the line many people dont turn of gas bottle although probably better if you do but you wont have a problem