Other than German, English strictly distinguishes between technique and technology. In German, both resolve to "Technik", while the former meaning is, in a lot of uses, probably better translated as "Methode". This obviously has some influence on derived adverbs and adjectives.
technically is the English adverb for both technique and technology, while technisch is the adverb/adjective mainly for the technology part of the meaning of Technik.
Still, there are uses of -technisch outside the technology area in German that relate more to the "Methode" meaning of technisch:
Versicherungstechnisch gesehen ist das Problem lösbar
Die lerntechnische Kompetenz der Schüler ist beeindruckend
My comment above on the standing expression "to technically agree on sth" relates to the "Methode" usage in German. A direct translation to German "technisch einer Meinung sein" would however be commonly understood as "to agree on technical matters" rather than "to agree in principle". This applies to your example "technisch gesehen" as well (but, admittedly, a bit softer than in my example - "from a technical viewpoint" already in English refers more to technology than technique and is not so much a standing expression as my example)
So, in case the expression would be used outside of a technology area, I would agree (and, at least partially) assume it is an (soft, because technically speaking (sic!) not wrong) anglicism or a literal translation into a rather uncommon usage.