The swamp thickens....
When a claim is transferred (sold or given) from one owner to another it does not change from one type of claim to another. Neither a transfer of interest nor a claim amendment can change the type of claim from lode to placer. I seriously doubt the Nevada BLM would or could allow the type of mining claim to change from lode to placer. Read the regulations they are quite clear on these points, there is no gray area.
The new owners may have relinquished the lode claims and relocated the approximate area as new placer claims but there is no process that could change an existing lode claim into a placer claim.
The lawyer was correct. No matter what type of claim is located the first locator is senior and all things being equal the senior locator has the valid claim.