The wordings of those two rules are vague enough to let Celtic off the hook. In fact, per Rule H36, we could even take the blame as the home team:
"H36 The home club in any official batch must ensure, so far as is reasonably practicable, H36.1 good order and security; H36.2 that policies and procedures have been adopted and are implemented to prevent incidents of unacceptable conduct; and H36.3 that any incidents of unacceptable conduct are effectively dealt with, all at its stadium on the occasion of an official match.
"H37 Each Club must ensure, so far as is reasonably practicable, that: H37.1 its Players, officials, supporters and any person exercising a function for or connected with the club do not engage in unacceptable conduct at a stadium on the occasion of an official match; H37.2 it identifies any of its supporters who engage in unacceptable conduct at an official match; and H37.3 it takes proportionate disciplinary measures in respect of supporters so identified in terms of Rule H37.2."