I believe this particular incident happened as soon as they took the contract for that particular carrier. Yes, there should be someone allocated to moniter and ensure that all paperwork is current and in stock, but that never happens at Aviance, who would struggle to cover the flights every day, let alone have time to do office work.
The point here is that the contract was taken on without proper thought or planning, so when a despatcher went to the management and told them "we can't trim these flights because we don't have the correct trim sheets" Rather than back up their staff (and the safety regulations) by telling the customer airline the truth, they just tell the despatcher to get it done regardless. Don't for a second assume that they will take the heat if something goes wrong.
You can't really blame the staff especially when they rarely get enough notice to even ask "do we have everything we need?" before they are 'selected' to go out and despatch a flight, let alone get trained for the a/c type, L/C system and procedures.