He told me that he may attempt to send bitcoin the day before or the same day but not sending the full 50 BTC
The owner isn't someone familiar with bitcoin / I asked him about the last two transactions to 1EF3DDBaPzbpJ5cXHVW2gZkyG1Jd4FotFW with low amount and he told me that the transfer was initiated by him .
Honestly, your friend's memory may not be 100% accurate at this point in time... The additional transactions for the smaller amounts were after the 49.5 BTC transaction: