We have 2 different situations above:
Yourself - Undergoing comlpex training in an aircraft, agree you are PUT and instructor P1 as you did not (I presume) hold a complex signoff prior to your training with the instructor.
Your mate -
He is also a JAR PPL but his currency on that aircraft had lapsed. His time can only be logged as "P U/T" and not "PIC U/S". Again the instructor will log "P1".
How has his currency lapsed? If you mean that in the flying clubs eyes it has lapsed (i.e. not flown for 28days, etc) then that is
their requirement to allow him fly their aircraft - however that is all, his PPL SEP has not lapsed. This is where club/group differ, if he had been in a group and gone up with a group member, as a safety pilot, he would log P1. Likewise if he had taken the local instructor up in his group aircraft to act as safety, with no instruction recieved, then again he would be P1, not the instructor.