Hi just found secound account RichardG
He just sent me test BIS from account b0518cd63935f081d8bc0271c9d861f51d636ed78ca43ba91d0f0233
check that topic https://bitcointalk.org/index.php?topic=1898984.msg20176591#msg20176591
Is your only evidence of a connection using that address, the statement from this user?
b0518cd63935f081d8bc0271c9d861f51d636ed78ca43ba91d0f0233 is his Bismuth address, four other guys got scammed by much larger amounts. You can query this address on bismuth.online
This, as is, may be inadequate for others. Primedigger needs to clarify the situation a bit, i.e. which account(s) has he exactly dealt with.