Plain/Perfect Infinitive

Am I right in my understanding of the following sentences:

I expect to pass my last exam by June.= I expect that I will pass it by June. (I look at the situation from the present moment ahead towards the future) and:

I expect to have passed the exam by June.= I expect that I will have passed it by June (I look at it as if I projected myself forward into the future looking back) .

P.S. Some of the native speakers say that there are no cases in which it would be possible to put non-perfect form (plain Infinitive) with the presence "by X time". Some of them have got different opinion. WHO IS RIGHT? WHERE IS TRUE?