If this occurs then the tap will have a hard time cutting the threads. In this situation I suggest you drill a bit oversized. Sometimes a couple of thousands does the trick. Also the speed and feed that you used to drill the hole can make a difference. Some materials heat treat when drilled to fast or slow.
Coolant also effects the tapping process.
If your coolant does not have the correct lubricity then there will be more friction when cutting the threads. My recommendation when tapping a troubled hole is to use tapping oil. Just place an optional stop in your program and swab the tap and the hole with oil. This normally gets you out of the jam. Another solution can be the dwell that you programmed.