Electrum, until recently, truncated the wallet file before writing to it for each wallet save. This could leave the (possibly encrypted) seed in multiple blocks on the drive, depending on how often Electrum saved the wallet file, even if he shredded it. (Newer versions of Electrum create a new wallet file, and then unlink the old one, again leaving the seed in potentially multiple blocks).
MZ's questions are good ones.
Sorry But I am not a technical guy and I didn't get what you said
Anyway, "Shred"="Permanently Delete"! That's what I have heard till now! If that can be recovered either I am using an outdated technology or you are using a new one
In other words, whenever Electrum saves the wallet file, it does a normal delete, and then creates a new wallet file. If OP shredded his wallet file, he only shredded that most recently saved file. Other older copies of the wallet, as deleted by Electrum, might still be on the drive somewhere.