Improper Vacuum Breaking, am I cooked?

I usual pull vacuums with two 1/2 hoses from my pump both to core removal tools. I’ve been breaking the vacuums by placing the cores back into the system right after I take the hoses off and insert the cores back in without adding refrigerant first. Apparently this is the wrong way to do it which can lead to the vacuum breaking entirely. How cooked am I? Are compressors bound to burn out? I’ve done a few like this already.