I would think if they could use the drill they used to drill down, then yes. But it's not possible to use that. It would be even more dangerous than these microblasts, and there's no way to bend it, so they'd have to dig a platform 70 meters deep and wide enough to keep debris from falling back on them and then drill sideways.
As described before the drilling truck rig they used to go down typically uses long 30 foot sections of drill pipe each connected one at a time to make up a long drill column with a large specialized drill bit on the end. It can basically drill through any type of rock, and the reason it can make good progress is each section of drill pipe is very heavy so each time they connect another 30 foot length of drill pipe onto the long drill pipe column , then you have all that extra weight bearing down on the drill bit at the bottom which helps the drilling speed.
Depending on the diameter and length of the drill pipe they used, the weight can vary but assuming they used 30 feet sections of drill pipe, and using the linked chart below, lets say they only used a small diameter drill pipe of 4 inch diameter , that chart shows that the pipe is going to weigh 14 pounds per 1 feet of pipe. So a single 30 foot section of drill pipe would weigh:
30 feet X 14 pounds/ft = 420 pounds for each single length of pipe.
So as they went down, they had to attach multiple sections of pipe that screw into each other (with collars on each end). So even at 180 feet down while they were drilling, that is 6 sections of 30 foot long pipe , so the weight of the drill pipe column at 180 feet down =
6 X 420 pounds = 2,520 pounds
So they had the advantage of 2,520 pounds of weight bearing down on the drill bit at 180 feet down. And it gets heavier the further they go.
Going sideways with nothing more than jackhammers, hand tools, pneumatic drills, dynamite, etc. is a whole different story.
Below shows what the different types of drill bits look like that they would have had on the end of the drill pipe column.
Water Well Rotary Drill Bits
Below link shows some drill pipe specifications for an example.
OCTG - Drill Pipe | Mid-Continent