Sounds kinda like a "swim move" where the runner avoids the tag by pulling back the regular hand and brings the other hand over to touch the base.It's a hook slide where the runner pulls the left hand back that they would normally touch the base with. As they slide next to the bag they rollover onto their stomach and touch the bag with their right hand. The tricky part is keeping that right hand on the base.
You have probably seen this a bunch of times in baseball and softball. Most people probably don't distinguish between the two slides and just call them both hook slides.
Sounds kinda like a "swim move" where the runner avoids the tag by pulling back the regular hand and brings the other hand over to touch the base.