OK, I guess there technically was a SG-1 crossover. Not significant to a SG-1 episode though.
Kind of a trend with him. On Sanctuary, he played 2 characters in the same scene and you wouldn’t notice it if you didn’t know.
So, his sister is played by his sister? How very meta.
Notice the last name of the first guest star that was mentioned. 
In Hot Zone, McKay was scripted to mention a brother, but David got them to change it in hopes of just that happening.
Love McKay’s niece’s reaction to him.
“You share credit now?”
Guessing that has been a problem before.
Well, I would guess that with McKay, it’s always a problem…
Nice echo of Eli’s introduction to the Stargate program. First time I thought of that.
Meredith!?!!! 
Great banter here.
“I solved your problem in my spare time, with finger paints”
“We’re at war.”
“Did you start it?”
“John Sheppard.”
“She’s married and she’s my sister.”
Bit of an assumption there, but better safe than sorry.
Well, it did seem like he was laying the charm on a bit thick there.
Nice Terminator pose from… Rodney?
Huh, that’s some hellacious FOD.
This is a bit over the top.
Bradley and Robbie? As in Brad Wright and Rob Cooper?
Yeah, I figured that was a bit of an inside joke.