The asbestos is in the glue, usually. As long as your friends didn't use a saw in the removal process, you should be OK. When the saw blade gets going, it makes dust out of the glue, hence, the hazard. Also, the blade will heat up the glue and may pose a secondary hazard.
Do wipe EVERYTHING down because you 'touch' EVERYTHING in the house. They should be aware of this and keep their hands away from their eyes and such. My best to ya and hope this helps.