According to Riot Employee “Riot Husker”, it is possible to get banned for asking teammates or the enemy to report another player.
Husker brought up this issues when replying a forum post created by a player outlying the “wave of posts over the last few days about the confusion that surrounds the reporting system. In particular around report calling.” The player does not have a sure stand on report calling, but he does state that Riot should have set guidelines for the issue, and not simply consider it as unsportsmanlike/negative behavior .
The player outlines that there is a lack of clarification about :
1) Report calling is punishable
2) One report is enough to trigger the report system, hence calling for “x9 reports” is unnecessary.
Husker replied by directly addressing the point that “Calling for others to report a player is a punishable offense” as “It is a form of bullying and as such is against the summoner code.” He states that if someone is to report a player, it should “be a personal decision” in deciding if “another player warrants a report” and that asking teammates or enemies to report someone else is “in itself counts as harassment”. Husker carries on to say that report calling is not acceptable as “Flaming and bullying a player will never help them to improve their game mechanics, communication etc”.
I don’t think players should be punished by reaffirming that a AFK or toxic player should be reported. Report calling ensures that the player’s case will be brought up to the tribunal and determined, as there are more complaints about he/she. Reports and bans also helps get rid of the toxic community or at least discouraged them from playing the game so the rest of the community can enjoy the time they spend on League. Eventhough you can get punished for report calling, I think it’s unlikely you will unless you are extremely aggressive about the issue.
Keep up to date through Facebook as there will be a follow up post since Riot Husker stated in another reply that a team will be creating a post regarding the issue soon.