The "to~" infinitive always implies the future, except for preference Like and Love

I think your colleague is wrong. Somebody has noticed a partial pattern and has elevated it to rulehood.

The use of infinitive (with and without to) vs gerund is purely syntactic, depending on the subcatgorisation frame of the matrix verb. It is only incidentally and weakly semantic.

A fellow teacher said to me that the to~ infinitive always implies the future.

The teacher is wrong.

By their very nature, "to" infinitives do not have a tense. Any time frame comes entirely from the context and usually the active verb.

He will tell me how to do it. / He is telling me how to do it. / He told me how to do it.

There is a "past infinitive using the "to have" infinitive: "To have lost one parent is unfortunate." but the "to have" infinitive, itself does not have a tense.