The fact LE were looking for TB and found him very soon after getting a search warrant, and setting foot on DM's property, LE at that point had no need to search further. A search warrant written up by the judge or JOP would be very specific and to go beyond those specified perimeters would be a huge risk which could lead to having potentially important evidence thrown out by the defense or judge. I believe the property is what the warrant was written up for and however LE found out about DM's property, it seems apparent there was a pretty strong indication TB was there in order to get a warrant.
Once TB was found, there would be no validity to continue the search other then for evidence within the warrant's recommendations. I am to believe the barn would not fall under that warrant as it is a separate entity from the farmland. If LE have a warrant to search someone's house, it does not include your sheds or garage IIRC. LE may have walked through the barn and the property surrounding the barn as other LE were heading back to the bush area of the property, but once TB was found and nothing obvious on of crime upon walking through, they probably did not have the right nor a warrant to do a search of the barn. MOO and HTH.
[I
]Description of the Place to be Searched
A warrant of a premises must accurately describe the location to be searched. If it fails to do so the warrant will be invalid.
The sufficiency of the description of the place must be assessed based on the face of the warrant, separately from the contents of the ITO or the manner it was executed. Failure to name a place on the warrant "is not a mere matter of procedural defect, but so fundamental as to render the document of no legal effect.
Description of Thing(s) to be Seized
The warrant's description of things to be seized "operates as a guide for the officers conducting the search."
The justice of the peace loses jurisdiction where the description is over-broad or too vague such that it essentially allows the officer to conduct a "carte blanche" search for any evidence within the premises.
http://en.wikibooks.org/wiki/Canadi..._Practice/Search_and_Seizure/Warrant_Searches