I figured out what happened. User error, but I feel like some instructions are half complete, that induced it.
1) Convoy stops if you don't destroy the targets fast enough and this leads them crashing into one another at times
2) Target "Roadblock" is presented, that only the 2X ZU23 and MANPAD need to be taken out, while for the trigger to be activated you also need to kill all infantry and buildings (1X building, 2X guard tower, 3X tent). The trigger should be modified or simply stated in the instructions somewhere (in a logical place), that all of the buildings and infantry have to be destroyed as well.
3) The UH60 RTBd, because last time I never triggered the ROADBLOCK DESTROYED action, since I only killed the MANPAD, AAA and infantry. And even though I cleaned up all the targets, the UH60 wasn't cleared to the LZ, since the Roadblock trigger wasnt't activated and it went BINGO.