I assume that you refer to the technique where you pull uke's lapel under his armpit, diagonally across their upper back and around their neck.
The rule says clearly that we are not supposed to apply the choke with the belt or bottom of the jacket, which is different from using them.
The essential thing here is how far around uke's neck you go: if you grab the lapel at the same side where it is coming to the neck (side opposed to the armpit the lapel is pulled hnder) and having your own arm/wrist at uke's trachea, no harm done. If you grab the lapel on the other side, pulling it across the trachea, you are using it as a garotte and no matter how you do it, I'd consider it basically the same as shown in the pictures. The rules say your own or your opponent's jacket, so applying the same thing with a different jacket does not change anything.
The tricky part here is that it is really hard to make out from the outside what you do exactly, especially in real-time. It is only some inches (or one inch even) between legal and illegal. Additionally, your body covers the whole thing almost completely so that there are few angles from where you would even have a chance to see a violation of rules. This makes it hard for a referee to sanction in this particular case if it is not very obvious, eg. someone violently pulling with a grip at the very end of or extremely low at the lapel.
That being said: One may well encounter techniques many times that are technically illegal since there are levels of competitions where the referees are not exactly high level and only visit one seminar every few years (if they are licensed at all).