My friend, you're being naive.You can fit a lot of explosives in one of those long distance hauling trucks, and the explosion seems to originate right ontop of the truck. The thing I don't get is why would Ukraine resort to an undeniable and hugely taboo act of terrorism with a suicide bombing? They won't be able to defect the attack to another party like the case of the car bomb that killed Dugin's daughter where they denied responsibility and said it was a rival faction of Dugin's. Ukraine had made it clear in the past they wanted the bridge destroyed and there's no other party to blame. I don't see how the EU would be able to continue supporting Ukraine and continue to provide them with weapon if it's shown that Ukraine did this car bombing attack on an civilian target which seems to also have killed a few civilian cars behind the truck. The only thing I see is that they'll blame it as a Russian false flag and pull up precedent of the Russian apartment bombing that sparked the 2nd Chechen war.
EU will not see it as an act of terror. This will not be seen as an act of terror hence nothing changes. Rule based order is selective, it's not international law based order. They will not do anything. Ukraine has already claimed responsibility. Support will continue. Nothing will change.