How long dd the engine go with a lack of oil? There was probably still oil left in it and if there was i wouldn't worry about engine problems later on. Id only worry if there not a drop of oil left and driven for a few minutes at a high speed that would really screw it up. Sucks about the work, atleast i am decent mechanic and double check my work before it leaves my bay.They did a half *** job cleaning it for a dealer, id want a full refund anf pro detail though. Oil these days is better then long ago, a little oil can go along way. Not all the oil would escape through the block and filter.Keep an eye on noises and everything from the engine