Proper way to uncheck a checkbox in Capybara

What is the proper way to uncheck a checkbox in Capybara integration tests? I have a list of checkboxes that I need to uncheck. I have selected them all using all:

checkboxes = all("input[type='checkbox']")

In order uncheck each one I use each. According to the information I have found on the StackOverflow there should be three ways to uncheck a checkbox:

uncheck(field)
field.click
field.set(false)

In order to test whether these different methods I created the following tests (each of these was in a separate scenario on the same page):

Using uncheck it succeeded:

checkboxes = all("input[type='checkbox']")
checkboxes.each { |field| expect(field.checked?).to eq("checked") }
checkboxes.each { |field| uncheck(field[:id]) }
checkboxes.each { |field| expect(field.checked?).to eq(nil) }
puts page.body
save_and_open_page

Using click it failed, so I assume this is an improper way of unchecking the field:

checkboxes = all("input[type='checkbox']")
checkboxes.each { |field| expect(field.checked?).to eq("checked") }
checkboxes.each { |field| field.click }
checkboxes.each { |field| expect(field.checked?).to eq(nil) }
puts page.body
save_and_open_page

Using set(false) it succeeded:

checkboxes = all("input[type='checkbox']")
checkboxes.each { |field| expect(field.checked?).to eq("checked") }
checkboxes.each { |field| field.set(false) }
checkboxes.each { |field| expect(field.checked?).to eq(nil) }
puts page.body
save_and_open_page

I figured I would just use uncheck, but then I noticed something strange: the page.body still showed the checkbox as checked, even though I had asserted in the test that checked? was nil. save_and_open_page showed the same thing. It appeared as if the checkboxes had not changed since the page was loaded.

Questions:

• Why aren't uncheck and set(false) altering the form HTML? In order form my test to pass some element associated with field had to be unchecked. Is there some disconnect between page.body and what uncheck deals with?
• What is the canonical way of unchecking a checkbox? Since uncheck is part of the API and is easy to use it seems to be the proper function to call for this sort of thing, but the fact that it's not changing page.body concerns me.

Related questions:

• How to check a checkbox in capybara?

Thanks in advance!