Why portscan detects from the wrong host?

Portscan reports detections from the wrong host. It says "detected by: asl.domain.de". Is this a bug? I pasted the email received from it

A T T E N T I O N
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Portscan detected:
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   System Date: Oct 26 2001
   System Time: 12:28:55

     Source IP: 62.226.51.184
     Target IP: 

   detected by: asl.domain.de

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