Other mistake: When Dr. Carter is dialing the Asgard, the chevrons spin and lock in, but the screen only shows 7 chevrons locked in. The Asgard required 8 chevrons to reach them.
Other mistake: When the Asgard arrive to save the day they start by beaming out the Goa'ould but Teal'c gets left behind. He should have been beamed out with the rest of them.
Suggested correction: The Asgard know about Teal'c from the season 2 episode "Thor's Chariot". In that episode they upload his DNA profile into the Asgard computers so that he is not beamed away with the other Jaffa in that episode. His profile would have been kept so that he would known in any future contact situations with the Asgard.
This correction seems to have been made without watching the episode (or remembering the episode). The Asgard spoken of are from an alternate reality when they never met Teal'c (and don't have his DNA). One could suggest that alternate reality Carter told them about Teal'c, but there were two of them, and she wouldn't have known alternate reality Teal'c was later killed.
Other mistake: In the last few minutes of this episode, Carter uses the DHD to dial home. She enters the first chevron, then the "Cannon" dies. And when she proceeds with the dialing,the first chevron is still encoded, and you can hear that she enters seven additional chevrons, which gives an equal of eight chevrons, and then engages the stargate. That would mean they are in another galaxy, referring to S02E15. In that episode they tried to dial the eight-chevron address from SGC but the computer wouldn't accept it. So, it is impossible that they would be in another galaxy.