The Record
Verified (by my browser, from Ciro Santilli's page): an ASCII portrait of Len Sassaman plus tribute text, signed "BitLen", was written into Bitcoin on 2011-07-30, weeks after his death. It can be found in the raw block data (bitcoinStrings.com/blk00003.txt).
Not yet verified: the exact transaction hash. I will not state one until I have seen it from a source. A receipt that is guessed is not a receipt.
Corrections to the myth of invention: Sassaman worked on Mixmaster and anonymous remailers, was known as Shmoo, and was married to Meredith Patterson. The rumor that he was Satoshi is a rumor, not a record.
Source: https://cirosantilli.com/cool-data-embedded-in-the-bitcoin-blockchain/len-sassaman-tribute