If anyone wants to see how Zerocoin transactions look like on the blockchain:

Check out a sample mint transaction where 50 coins go into a blackhole.
http://explorer.zcoin.io/tx/b827e91bee75e4abae8590206b088f05f6b9c563dc56e5e71c42da9523ebcccd
https://chainz.cryptoid.info/xzc/tx.dws?b827e91bee75e4abae8590206b088f05f6b9c563dc56e5e71c42da9523ebcccd.htm

This is a sample spend transaction where 50 coins come out from the blackhole and have no linkage with its mint transaction or any history at all.
http://explorer.zcoin.io/tx/d75cd4bfae85bc278900eb4728f71eedea1dec2a16d3f18551dfcd43b413ac07
https://chainz.cryptoid.info/xzc/tx.dws?d75cd4bfae85bc278900eb4728f71eedea1dec2a16d3f18551dfcd43b413ac07.htm

The point is that the 50 coin from the Zerocoin spend transaction could have come from any of the people who minted 50 coins giving it very high anonymity.