Please provide cites and the evidence on which you base this.
And you know this… how? It is not even certain that it was a truck rather than a boat/barge/drone.
Way too complicated a plan, with too many opportunities to be discovered.
The Russian claim is typical of over-elaborate lies.
It’s easier to hide under the lower road if you’re going by water?
Pretty sure the Russians will minimize any video showing actual damage to the bridge in any detail.