Phase "invertion" or "flipping" is not the signal upside down. Phase invertion DOES NOT exist. You should understand the differance between phase and polarity.
It seems like a stupid matter of terminology but it's not ...
In reallife audio there is no such thing as phase inverting. You can SHIFT phase on a certain frequency but this is a whole other story. In a one frequency signal (eg. a sine) a phase shift of 180° has the same results as inverting polarty. Phase is merely a time based aspect expressed in °
You cannot "invert" seconds or minutes either.
Now inverting polarity (cold<->warm) is a method used to compensate for time differences caused by the different dinsances from mikes to their source or to to prevent fequency cancelling caused by mics that are oposite (eg top/bottom mikes). And SOMETIMES it might work.
This whole phase theory is way too complicated so it's best not to confuse the terms, you'll only make it worse....
Now back to your question
"dynamic pointed at the kick beater" ... as in the rear of the microphone pointed at the kick? Otherwise it's quite logic that your snare sounds better polarity inverted, and that it cancells the kick.
Just try to get the best sound. No matter if you invert polartiy or not. Just make sure you check the interaction with other mics (eg. kick, OH's etc...)
greets, arno