'paintless" dent removal frequently turns into painting your door in the cold. If the dent guy used a heating tool...or even took it into an inside bay it might not have cracked. This depends mostly how deep or "sharp" the dent was. If it was shallow it shouldnt hav mattered...a deep dent though only a couple really good dent guys I know can get them out.
DentMasters does really good work from my experience. There are a ton of PDR companies around the area though that I have seen good/bad work from. Dentclinic, Dentworks, Dent Terminator, Dingking...well there are many others too.
It really depends on who is doing it...i have seen guys from each company make a dent disappear...and then another guy from the same company make a dent look worse..