So, this is an interesting development, O'Neill impregnating a peasant.
I don't recall that the baby was his (100 days isn't long enough, barely more than three months), but it has been a long time since I've seen that one. I'll have to rewatch.
The main problem I have with the episode, which was otherwise excellent, is that if you can just open up a buried gate and dig your way out that easily, why have they kept telling people to bury their gates to keep the Gou'ald from coming back?
At best I'd offer that a gate buried in rubble would just clear out some of the rubble, allowing the rest to collapse back down, but in that case the Goa'uld would just keep redialing till the gate had swalled a clear path to the surface. Another option they'd use is to send in a mining team, let them work till they die, and then send another mining team to continue, or even send a DHD through and let the miners come and go (unless perhaps a buried gate's chevrons can't move freely enough to engage, or the ring isn't free to spin, or something.