Hmmm. Are there two separate ways of freeing? It seems very strange to say that either by mistakenly giving or by intentionally leaving clothes one can free an elf. Surely either a maisah nesinah or a kavono leshachrer should be good, but not both!
Its not a choice between a ‘maisah nesinah or a kavono leshachrer’. In both cases there is a ????, with the ??? coming to the hands of the elf. However, the House-Elf must, in Dobby’s words, ‘receive clothes’. The key lies in the word ‘receive’. The ???, in this case the elf, must be ???? clothes from his master. This ???? could either be through a ????? ??? ????, which does not require ????, or a ????? ?? ??? ????, which in order to be a ???? must be ?????. As in both cases the requirements of the elf ‘receiving’ clothes has been met, so there is no problem with the two separate forms. The ??? is ???? on ????? ?????, not ??? ?????.