I decided to download your latest video to my computer, and I used my swing analyser program to study your swing in depth.
I found one flaw in your last swing that could predispose to pulling.
In your first two DTL swings, you have an excellent downswing pivot action (hips first, shoulders second) and you have a good posture at impact. Images 1/2 shows that your pelvis is open and your shoulders less open. However, in your last swing (see image 3) you can see that your pelvis stalled in the downswing, and it failed to complete its rotation even though your arms are now fully extended towards the target in the finish phase of the swing. That failure to rotate your lower body well started in the early downswing and it seemed that your upper torso was rotating much faster than your lower torso, which means that your kinetic sequencing was out-of-synch in that particular swing. That type of error would cause the equivalent of an "upper body dive" swing, which causes an out-to-in swingpath through the impact zone and a pull if the clubface is square to the clubhead swingpath. It is difficult to tell if your clubhead swingpath was out-to-in in that particular swing because it was not DTL.
Here is a photo showing the results of an "upper body dive" movement where the upper body turns much faster than the static lower body.
Jeff.