It is not necessary to convict Sam or Lydia in order to convict Yuri of bypassing all the seals or even mention the Day Breaks' helping WItness with his demon conspiracy.

There is enough evidence between Yuri and Dainonigate to convict him of bypass the second, third, and fourth seals. Yuri's helmet, Phone records, and testimonies from Dainonigate provide enough evidence without having to divulge the fact that Lydia and Sam also went into the penthouse.

Honestly, you could probably save a lot of time by skipping gathering the Day Breaks' evidence all together except for the flesh lump which you need for Witness. It would also save time on having to do Sam's Hangout segments to learn that Witness gave him the flesh to hold since there would be no reason to bring up that fact in court as Witness' conspiracy can be solved with just a few pieces of evidence.

It just seems unnecessary to go through the extra steps to get the Day Break evidence when it does take you a fair bit out of the way.