Redemptionis Sacramentum says the following:
[44.] Apart from the duly instituted ministries of acolyte and lector, the most important of these ministries are those of acolyte and lector by temporary deputation. In addition to these are the other functions that are described in the Roman Missal, as well as the functions of preparing the hosts, washing the liturgical linens, and the like. All, “whether ordained ministers or lay faithful, in exercising their own office or ministry should do exclusively and fully that which pertains to them”. In the liturgical celebration itself as well as in its preparation, they should do what is necessary so that the Church’s Liturgy will be carried out worthily and appropriately.
Now, one could argue that an instituted acolyte may be deputed to act as an EMHC - in which case one would expect that the acolyte would know that this is within his remit and that he would have received appropriate training. At any rate, it would be inappropriate, in my opinion, to ask (or make, as the o.p. said) a server on the spot to carry out a function which is not proper to them - incidentally, if one was to follow the recommendations of Redemptionis Sacramentum, the server in question would have been holding the paten under the chin of the communicants, not distributing the Precious Blood [R.S.93].
Even if it were appropriate for the o.p. to take on another extraordinary function in the Mass, he would be completely within his rights to politely decline if he felt uncomfortable giving out Holy Communion, touching the sacred vessels or the Sacred Host, etc. etc.
This confusion also causes me to return to the point I made earlier: if there were no deacons or EMHC’s to distribute the Precious Blood, the priest simply should not have offered the Chalice to the faithful, as there is no obligation upon him to do so at any Mass. In fact, Redemptionis Sacramentum specifically gives lack of EMHC’s as a reason not to offer the chalice:
[102.] The chalice should not be ministered…wherever access to the chalice would be difficult to arrange, or where such a large amount of wine would be required that its certain provenance and quality could only be known with difficulty, or wherever there is not an adequate number of sacred ministers or extraordinary ministers of Holy Communion with proper formation.