Tethering, via a phone without paying for "Mobile Hotspot" is a violation of the Terms of Service (TOS), plain and simple. If you have the 'unlimited' data plan, and you signed the TOS, you agree to follow Verizon's meaning of 'unlimited'.
I know I violate the TOS each time I am at my Mother's house and spend a few minutes tethered each day I am there.
In a way, this seems to mimic 'speeding' and avoiding traffic tickets. On interstates, I, and many people, knowingly exceed the posted speed limit. However, we see that there seems to be a higher speed limit that must be crossed before a ticket is issued and we stay within this 'safe' limit. We are breaking the law, period! The same with tethering, it is a violation, but we do it anyway. Many try to 'stay' under the radar, but those that get caught, pay!
Just my opinion, I am sure yours will vary.