That doesn't happen anymore. I tried it multiple times.
It still happens, I just did it.
The enemies have to be behind a turret for it to work. Normally if there's a prop in the way soldiers will just walk around until they get a clear shot. This makes sense. People holding a turret don't get up and leave and start looking for you if you take cover. This also makes sense, leaving the turret makes them vulnerable. The problem is caused because the game does not treat ducking behind a crate and holding a potted plant in front of your face differently - in both cases you're treated as if you are behind cover. You can walk up to somebody on a turret and hit them in a head with a crowbar to this day.
To be fair this isn't a bug with the enemy intelligence. It's what is cover and what is not being defined well enough. The game could flag a carried object as something being carried rather than as standard cover and then have regular enemies strafe you and turret enemies continue firing.
There is another bug shown in the video as well - holding an object in front of a mobile enemy's face will cause them to strafe to try and get a "clear" shot at you even if it's just a wooden clipboard or a soda can.