I speak French. If it is spelled touché, then it is the past participle and it is pronounced 'toosh-ay'. While there are somewhat exotic conjugations (viz: subjective and imperative), 'touche' would be the present form of the indicative tense and it makes sense that French influenced refs would use that tense, since the touching is in the here and now. Touché, as an single word acknowledgement of a point being scored at your expense in a debate, still originates from fencing, even if it isn't the tense used by Olympic judges.

You probably knew all that, but I had to go digging anyway to make sure I wasn't getting dotty in my old age.