So here is the link for the Ontario Fish and Wildlife Act:
https://www.ontario.ca/laws/statute/97f41
and the Hunting Regulations :
https://www.ontario.ca/laws/regulation/980665#BK2
There is a section in the hunting regulations devoted to hunting in a party and a section specific stipulates this very issue:
22.1 If a member of a party kills a species of big game under the authority of a licence that is held by another member of the party, the holder of the licence shall,
(a) immediately after the kill and at the site of the kill attach the seal provided with the licence or licence tag to the wildlife in the manner indicated on the seal; and
(b) keep the seal attached to the wildlife while it is being transported. O. Reg. 32/04, s. 4; O. Reg. 54/10, s. 7.
This is how the situation you guys are talking about is going to be judged on. In my opinion, there has to be three conditions for the immediate tagging to enforced. One, the hunter has to be in a party and the party has to have a proper seal for the animal killed. Two, the hunter(s) have to be have killed the animal and at the kill site. Three, the seal has to be present for the tagging. Gilroy has presented a condition where the seal has to be humped through terrain. Until the seal is actually present, the condition of immediate doesn't qualify. Now once the seal gets there, any delay on tagging the animal, you run the risk of a CO charging you. For example, I am sure the CO wouldn't care if the guy who had to hump 4km stopped to catch his breath, especially if he is an elderly person (but I would if he had to walk 4km or if there were other options, like an atv ride, to go get him simply so he didn't have to walk that distance). However, if the guy stopped to open a congratulatory beer after his walk rather than the seal, well, then the CO could decide to lay a charge depending on his mood. Most groups have the tag owner/holder somewhere in the middle of the group so they can get to the kill site with the least amount of fuss.