Yes. Prices in history files are no bar periods, but single ticks, although with an open, close, high, and low. A tick is valid until the next tick.

If a tick has a time stamp at exactly a hour boundary, it can fall in either the previous or the next bar period, dependent on rounding. In the latter case the bar period ends with the previous tick. At least I would interpret it so.

But I'll let the developer check if it is really so, and modify it so that the same tick is always at the same side of the boundary. It's not relevant for backtests, but nicer.