I think it was also filled with mud , or is it what you cover with the “no tether points” part ?
My take away from the article is that there could have been many more solutions, some more clever, some involving more gear etc., but they were completely short of time and verified information to come up with other viable plans.
Basically any other plan would have needed more checks, preparation, waiting for the gear to be ready, rehearsal, etc. And as said in the beginning of the interview, they feared the kids would be dead any day. As I get it, that’s also why civilians where chosen instead of the pro rescue team, because they were the only one with appropriate gear and experience at that moment in that place.