The pronunciation of these two words is the bane of many a Ba’al Koreh. You sense everyone waiting to pounce on the wrong pronunciation (which itself its wrong, because it should come from the Rav or his designated “corrector” on the Bima. Some Parshiyos are a breeze, and others are a nightmare. This is compounded by some Ashkenazit pronunciation where one can barely discern the difference between a Tzeyrey and a Segol.
I was very interested to read, in the newly published Mesoras Moshe, where a particular Ba’al Koreh was layning with R’ Moshe Feinstein in attendance. He had made a few errors between the two words, and yet R’ Moshe declined to correct him.
Afterwards, he approached R’ Moshe and asked for the reason behind the lack of correction. Reb Moshe answered that the difference between the two words in the context of layning, is that one has a musical trope (cantillation) while the other does not. Reb Moshe then viewed the error as being one of trope! As such, according to many opinions, trope errors need not be corrected, let alone re-read.
It was fascinating. Your mileage may vary. Certainly wherever I’ve been, the “vultures” have always been ready to pounce. Reb Moshe’s greatness and individuality shone forth, and I enjoyed his observation!