ie ...even though he may have been misinformed, but he did not lie...
Depends on how may is combined with have in a sentence ( ie also author's intent ).
may: define ...used to indicate possibility or probability <you may be right> <things you may need> --
..."flame may have elements of a normal message, but is distinguished by its intent".... ..."a normal, non-flame message may have elements of a flame -- it may be hostile"... http://en.wikipedia.org/wiki/Flamewars