I can't knowledgably speak concerning the court order, but as far as state law goes, I perused 39 pages of the Minnesota firearms laws, and couldn't find any reference to a courthouse or jail being off-limits.
Not at all sure the officer knows what he's talking about.
Places Where Pistols are Off-Limits or Restricted even with a Permit to Carry
Despite the general rule that permits to carry pistols are valid statewide, pistols, or other firearms, are nevertheless restricted or not allowed in the following places:
· Correctional facilities or state hospitals (Minn. Stat. ‘ 243.55)
· County jails (Minn. Stat. ‘ 641.165)
· Courthouse complexes, unless the sheriff is notified (Minn. Stat. ‘ 609.66)
· The Capitol area, unless the commissioner of public safety is notified (Minn. Stat. ‘ 609.66); “capitol area” is defined in Minn. Stat. § 15.50, subdivision 2.
· Afield while hunting big game by archery, except bear (Minn. Stat. ‘ 97B.211)
http://www.house.leg.state.mn.us/hrd/bs/83/SF0842.html
Additionally, firearms are not permitted in federal court facilities or other federal facilities (Title 18 U.S.C. ‘ 930). This is just one of many federal laws regulating firearms. Federal law must also be consulted to ensure compliance with all applicable firearms laws.
If he notified them(and I read that he did)he should be in the clear. Hopefully done via certified mail.