We are able to repro this bug on build 54.0.2798.0 Canary and on 51.0.2704.104(Stable) in iPhoneSE iOS 9.3 
Lock icon stays green even when there is no internet connection.

I wonder what's the expected behavior on other platforms. Is lock icon staying green when there's no internet connection considered "expected" behavior.

When I reloaded the page while there's no internet connection, I expected the padlock will refere to that page it's not secure (because there's no internet connection) as in "expected.png"

Deleted: expected.png 1.8 KB

	expected.png 1.8 KB View Download

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/b78945177b2845d9197b6f353d39e7d92dc6f2c2

commit b78945177b2845d9197b6f353d39e7d92dc6f2c2
Author: eugenebut <eugenebut@chromium.org>
Date: Wed Jul 20 22:48:29 2016

[ios] Reset SSLStatus to default when navigation fails.

This prevents showing green SSL lock if previously loaded secure page
has failed to load.

BUG= 628471 

Review-Url: https://codereview.chromium.org/2165443002
Cr-Commit-Position: refs/heads/master@{#406701}

[modify] https://crrev.com/b78945177b2845d9197b6f353d39e7d92dc6f2c2/ios/web/web_state/ui/crw_web_controller.mm

Verified on iPhone 6S iOS 9.3.2, iPad4 iOS10 . The lock is no longer seen when there is no internet connection.

Thanks for the quick fix!