I know, but I use it offline, so I don't need to send transactions from it, I just sign transactions.
I was not talking about implications of running potentially malicious client offline, of course that would be stupid. bob123 was saying that Electrum that comes with tails is outdated, meaning that it probably can't send transactions, since servers would reject them to incentivize users to upgrade to newest versions that don't have the infamous phishing vulnerability. But it works for signing transactions or creating new wallets just fine.
oh yeah of course, that is the only thing that matters as long as you are sure that the preinstalled version is legit. but i was just pointing out the main question here regarding "verification of the already installed Electrum on Tails." and how you couldn't be sure about it so there are still ways to lose money even if you were offline.