Was Tim McVeigh a homicide bomber? I suppose so. After all, he did kill 168 people.
But he lit the fuse and walked away. Suppose, instead, that, stoked up on Allah, he'd been motivated to drive the truck straight into the building lobby and kill 268, perhaps, instead of only 168. He'd still have been a homicide bomber. But a more specific designation would be available: suicide bomber. Nothing euphemistic or PC about it.
Words are funny. Recently, a friend referred to the BLU 82 as a "15,000 pound martyr maker". I wondered why I chuckled at his use of the word martyr. I think I must have enjoyed the implied sneer at the twisted religiosity of the bomb's intended victims.
Suicide bomber is PC euphamism. The purpose of his actions is murder, not suicide. The news should say "15 innocent civilians were murdered today. State sponsored murderers from the Palistiniam Authority murdered 15 innocent people when ..." Murder of civilians is the goal, intention, and result. Thus even the term "militant" is misapplied - these cowards go after little girls and people on buses - they never attack a military installation.
Homicide bomber is euphemistic in its own way - murder would be more accurate - as in "First degree murder" which is what these are.