What Happened to Phil and Max and their friendship?

From 2006-14 they were had a close friendship and even teamed up to get rid of Jack and that Carl White and had a lot in common. Then from 2015 onwards the producers decided to turn them against each other plus Phil even bribed the foreman for Max to go down for Lucy's murder in the process. I found it so weird that one minute their close and the next they are at loggerheads.