@captain_crunch - Valentino was involved in
uranium Elradite smugging.
He used Cygnus, an easy to recognize catamaran, as a drop-off point, to avoid making direct contact with the smugglers. It's a common technology known as "dead drop".
Cygnus was peacefully sitting in a dock all the time, and it was fine. But now it was suddenly taken out for a competition, and there was a high chance the contraband was going to be discovered.
His plan A was to marry the girl in charge of the boat and get the boat and the beautiful girl too. This didn't work out.
So his plan B was making the girl sell off the Cygnus to pay off her debts. But she managed to get into a race with a huge prize.
So he had to sabotage the race to ensure she doesn't win. Or at least sabotage her boat so that the contraband would not be found.
To make things worse, his sabotage was found out, and a more important noble got involved. He might have nobled his way out of the situation, but chose to flee using a horde of rampaging golems as a cover.
Now he's joining forces with a suspicious person to have his revenge.
I guess he could have ordered the items stolen instead, but he didn't have any thieves he could trust with elradite and a proof of his treason.