Bubble sort quiz: why the result is not the same?

[lupoalberto]

Here's a quiz of a Math professor on Twitter:



He says the results are:
1) 1 / 930
2) 1 / 14880

I did this code (python3) and while the first result is the same, the second is not the same.
I don't understand why the 2nd answer with my code is about 0.002.
I investigated my script for hours and i don't find any mistake...

Do you confirm that the code is right?

import random

def bubblesortOnePass(l):
    if len(l) == 1:
        return l
    else:
        for i in range(len(l)):
            try:
                if l[i] > l[i+1]:
                    l[i], l[i+1] = l[i+1], l[i]
            except:
                if l[-2] > l[-1]:
                    l[-2],l[-1] = l[-1],l[-2]
        return l

def bubblesortTwoPass(l):
    global counter
    if len(l) == 1 or counter == 2:
        return l
    else:
        for i in range(len(l)):
            try:
                if l[i] > l[i+1]:
                    l[i], l[i+1] = l[i+1], l[i]
            except:
                if l[-2] > l[-1]:
                    l[-2],l[-1] = l[-1],l[-2]
        counter += 1
        return bubblesortTwoPass(l[:-1]) + [l[-1]]

def generateList():
    L = []
    remaining = [i for i in range(1,41)]
    while len(L) < 40:
        random_N = random.choice(remaining)
        L.append(random_N)
        remaining.remove(random_N)
    return L

N = 1000000
totalOnePass = 0
totalTwoPass = 0
for i in range(N):
    L = generateList()
    f = L[19]
    K = L.copy()
    bubblesortOnePass(L)
    if f == L[29]:
        totalOnePass += 1
    counter = 0
    After2pass = bubblesortTwoPass(K)
    if f == After2pass[29]:
        totalTwoPass += 1

print("Probability after One Pass is {}".format(float(totalOnePass / N)))
print("Probability after Two Pass is {}".format(float(totalTwoPass / N)))