Punctual, or early enough? Two expressions that are not interchangeable
One small word separates arriving punctually from arriving with time to spare.
The train arrived on time, so we were in time to catch our connection.
These two expressions differ by one small word and mean genuinely different things, and the model sentence uses both so that the contrast is visible in a single breath. One of them means punctual: the event happened at the moment it was scheduled to happen, and the reference point is a timetable, an appointment or a promise. The other means early enough: something was accomplished before a deadline closed, with room to spare, and the reference point is whatever had to be done afterwards. The first is a judgement about a schedule; the second is a judgement about a consequence.
The third example sentence is the one to study, because it uses both expressions about the same journey and they do not contradict each other. The vehicle failed the schedule, so the first expression is negated; the travellers still beat the deadline that mattered, so the second holds. Learners who treat the two as interchangeable produce sentences that are grammatical but say the wrong thing, and in a work context the difference is not cosmetic: telling a manager that a report was delivered punctually makes a claim about the agreed date, while telling them it was delivered early enough makes a claim about the deadline it had to beat, and only one of those may be true.