Checking up on it again, he was happily surprised with some of the results:

I asked him again today via private mail and his response was swift. The whois entries for phpshield.com now point to his person and we can expect additional information on the web site itself soon. I like it when things can be resolved like that and I actually think this is a chance for his product rather than a possible competition issue.

This helps to more clearly define the difference between the PHPShield and SourceGuarian products. You can find out more information about each product from their sites - PHPShield and SourceGuarian. Both are encoding packages to help protect and distribute your code.

However, the phpShield.com home page did not offer the slightest clue who actually is behind that product. [...] It's common practice to whitelabel your solutions and sell them under different brands with different feature sets to different target audiences. However, we always clearly state who is behind the whitelabelled solution.

A little more digging shows an interesting relationship between the company that sells SourceGuardian and the company behind this PHPShield (Inovica). He sees the deception counting against the company and has just "struck one off the list" from his search for encoding methods.