This is the answer I got:
From logs it looks like it is a known malware so it is likely that it was also dropped by AV.
The way that it works is that while TE is emulating other blades might decide to drop the connection. By the time TE is setting the connection to drop it is no longer in the table and the blade does not know if the connection was dropped or not so it produces a detect log.
In the second time the file is in the cache so it is prevented at roughly the same time it is prevented in AV so there is no discrepancy in the logs.
Can you check if this makes sense in your environment?